As the United States tries to ramp up its troubled evacuation in Afghanistan, President Biden is expected on Friday to address the furor over the sluggish process, stymied by mayhem in Kabul and delays in Washington, that threatens to strand thousands of Afghans desperate to flee the Taliban takeover.

Mr. Biden, who is expected to speak at 1 p.m. in Washington, has defended the pullout from Afghanistan, while promising not to abandon Afghans who risked their lives by working for the U.S. government during the war.

The United States has rushed troops and diplomatic reinforcements to the Kabul airport in recent days to speed up visa processing for Afghans. American commanders are negotiating daily with their Taliban counterparts — the former insurgents they battled for nearly two decades — to ensure that evacuees can reach the airport.

But the reassurances from Washington belie the fear and futility on the ground.

Thousands are waiting fearfully outside the airport gates, where Taliban soldiers have attacked people with sticks and rifle butts. As Afghans clutching travel documents camped outside amid Taliban checkpoints and tangles of concertina wire, anxious crowds were pressed up against blast walls, with women and children being hoisted into the arms of U.S. soldiers on the other side.

Since sweeping into Kabul last weekend, the Taliban have moved swiftly to cement their control over Afghanistan, dispersing protests with force and hunting down opponents despite pledges of amnesty, according to witnesses and a security assessment prepared for the United Nations.

The group’s unpredictability and history of brutality have set off a rush to escape, especially among Afghans who worked alongside U.S. and NATO forces.

Two U.S. officials described growing impatience within the Biden administration over the State Department’s inability to process visas more quickly.

The visa system had a backlog of 17,000 cases when Mr. Biden took office in January. The U.S. Embassy in Kabul was processing at least 100 people each week until June before a resurgence of the coronavirus in Afghanistan halted the operation.

One of the officials also described the challenges faced by people who helped the United States in reaching the airport safely, given the masses of Afghans trying to evacuate and the Taliban checkpoints.

On Thursday, John R. Bass, the former ambassador to Afghanistan, arrived in Kabul with a small group of diplomats to speed up the visa processing. Diplomats are also going to Qatar and Kuwait, where U.S. military bases will serve as way stations for refugees and repatriates before they are sent to another country.

“This is an operation that will continue at as fast a clip as we can possibly manage,” said Ned Price, a State Department spokesman. He said American officials were continuously alerting Afghans who had been cleared to fly, including more than 800 on Wednesday night.

About 5,200 U.S. troops are securing the airport under the command of Rear Adm. Peter Vasely, a former Navy SEAL who speaks to a Taliban counterpart outside the airport several times a day, said a Pentagon spokesman Troops are also deployed at entrances to the airport, where they assist consular officers in reviewing documents, he said.

As of Thursday afternoon, the U.S. military had evacuated 7,000 Americans, Afghans and others since Saturday. The effort is well short of the 5,000 to 9,000 passengers a day that the military will be able to fly out once the evacuation is at full throttle, officials said.

“There are tens of thousands of Americans and Afghans literally at the gate,” said Sunil Varghese, the policy director for the International Refugee Assistance Project. “This could have been completely avoided if evacuation was part of the military withdrawal.”

Kabul was many things on Thursday. The chaos at the airport was matched by calm in other pockets of the city. Some businesses resumed work, and many people were trying to get on with their lives. Others were in hiding, afraid for theirs. Women were scarce. There were signs of some Taliban restraint, but also clear evidence that its members patrolling the streets were not afraid to wield force.

Aside from the vicinity of the airport — which remained a scene of mass desperation and danger — on a drive around Kabul on Thursday morning, the hum of the city had largely returned.

Markets were bustling, and traffic was jammed.

On the north bank of the Kabul River, about two dozen shirtless young men were preparing to engage in a ritual of self-flagellation. They were commemorating Ashura, a holy day that — although peacefully observed by millions of Shiite Muslims across the world — has in some parts of the Middle East been wracked by violence, with attacks by extremists bent on stoking sectarian tensions.

In Afghanistan, those attacks have targeted the predominantly Shia Hazara minority.

The youngest of the group on the Kabul River, a native of Bamiyan Province who identified himself as Mahdi, was just 12. He called an older attendant over and checked the blades on his Teekh, a set of five chains with knives on the edges, attached to a handle that people whip themselves with in the ceremony.

“OK, they’re nice and sharp — good work,” he said. “I am not afraid of the Taliban. They have no business with me — why would they harm me?”

As military evacuation planes buzzed overhead, the flagellation began, and the blood started flowing.

While Afghanistan has been beset by its own suffering in recent years, the bloodletting is meant to pay tribute to a fight centuries ago: In the year 680 in what is now the Iraqi city Karbala, the army of Yazid slaughtered Hussein, a grandson of the Prophet Muhammad, and cut off his head.

The Taliban are known for their uncompromising and harsh interpretation of Islam, and brutally persecuted the Hazara when in power from 1996 to 2001 — including a massacre of an estimated 2,000 people in 1998. But on Thursday they offered protection so that the ceremony could take place in safety.

Nearby, from the shadow of a drinks stall wrapped in black cloth and ornate with green and red flags, three Taliban members watched placidly.

Their commander, a turbaned man named Ahmad Zia, his beard dyed pitch-black, did not have an assault rifle slung around his shoulder — an oddity among the thousands of Taliban fighters who have flooded the city since Sunday.

Calm and with a swagger easily recognized as coming from the country’s south, he was chatting away with a few younger bystanders.

“I’ve been with the Mujahedeen for the last 12 years. Three days ago, I arrived from Helmand Province, I am from Musa Qala myself,” he said, referring to a district long infamous for being the Taliban’s headquarters in the country. “We are here to provide security 24 hours a day. People can carry on with their lives now.”

That sentiment was echoed at the entrance of a nearby mosque.

Nooria Jaan, a 30-year-old housewife, had come to the center of the city to observe the Ashura commemorations.

“I’m really happy right now,” she said. “This year Ashura is really peaceful. The criminals have disappeared overnight. There is no more crime.”

But later that afternoon in another part of town, the loud burst of machine-gun fire pierced the quiet.

A group of young men had tried to raise the tricolor flag of the ousted Afghan government. Their efforts atop a hill were violently broken up by Taliban foot soldiers, who let loose a volley of gunfire.

Three people had been shot.

One of the wounded sat in the passenger seat of a gray Toyota Corolla, its windows shattered from the bullet impact.

Another injured protester staggered down the hill, blood dripping from his hair and down his neck.

“The end of a Taliban rifle” he said, relating how he had been beaten.

As darkness fell over the city, sporadic gunfire continued.

As the Taliban cement their control over Afghanistan, there is a deepening fear among the country’s religious and ethnic minorities that the gains they made over the past two decades could be lost and that they could again find themselves the target of persecution.

Many Hazaras — Shiite Muslims who are estimated to make up 10 to 20 percent of the country’s population — worry that atrocities of the past will be revisited despite assurances from the Taliban leadership that they have changed.

“We are extremely worried and scared. Taliban have a history of violence against us,” one Hazara man who lives in Kabul said by telephone, not wanting his name used in public for fear of reprisals. “Now I feel I am a target for them. I don’t leave home unless it is very necessary.”

He said local Taliban officials had assured residents that civilians would not be targeted as they entered the area. But he said they had broken that promise. His father-in-law was killed by militants in Ghazni Province after the Taliban captured the area last month.

“He had not harmed anyone, he was just a teacher, a religious scholar and an educator,” he said of his father-in-law.

As the Taliban swept across Afghanistan this summer in advance of their blitz that culminated in the fall of Kabul, an investigation by Amnesty International has found evidence of the slaughter of nine Hazara men, raising fears of more bloodletting to come.

“On-the-ground researchers spoke to eyewitnesses who gave harrowing accounts of the killings,” which took place in early July in Ghazni Province, according to the report. “Six of the men were shot, and three were tortured to death, including one man who was strangled with his own scarf and had his arm muscles sliced off.”

One witness said villagers had asked the fighters why they inflicted such brutality on people. The answer from a fighter, the witness said, was that “in a time of conflict, everyone dies.”

The killings took place before the Taliban issued a blanket amnesty in Kabul this week, promising no reprisal killings and safety for all Afghans. It is difficult to know what is happening in much of the country since cellphone service has been cut in places and many journalists have fled or are in hiding. But there have been no reports of wide-scale attacks on Hazaras since Sunday.

And on Thursday, Taliban soldiers provided security in Kabul as Hazara men commemorated Ashura, a Shia holy day.

Yet the last time the Taliban swept to power, they exacted revenge on the Hazara population after taking control of Mazar-i-Sharif, a city in the north.

“Within the first few hours of seizing control of the city, Taliban troops killed scores of civilians in indiscriminate attacks, shooting noncombatants and suspected combatants alike in residential areas, city street sand markets,” according to an investigation by Human Rights Watch. “Witnesses described it as a ‘killing frenzy.’”

This time around, one of the Taliban militants’ first acts after taking control of the country was to blow up a statue of the Shiite militia leader Abdul Ali Mazari in Bamiyan Province, the Hazaras’ unofficial capital.

And with many Hazaras having adopted liberal values over the past two decades, said a Hazara woman who works for the government, “the threat we face now is much more serious than the 1990s.”

“I am worried about my and my family’s life,” she said, speaking by telephone from Kabul on the condition of anonymity, fearing for her safety. “I am very vulnerable: I am Hazara, a working woman, a liberal and an ex-journalist.”

“Hazara women have a strong presence in the society: They are university students, working outside, and are visible in the streets,” she said. “And this is exactly the opposite of what the Taliban want.”

In February 2020, eager to remove American troops from Afghanistan by the end of his term, President Donald J. Trump struck a deal with the Taliban: U.S. forces would leave in return for Taliban promises not to harbor terrorists and to engage in direct negotiations with the Afghan government.

Mr. Trump’s secretary of state, Mike Pompeo, attended the signing ceremony in Doha and posed for a photo alongside the Taliban leader, Mullah Abdul Ghani Baradar

Some former senior Trump officials now call that agreement fatally flawed, saying it did little more than provide cover for a pullout that Mr. Trump was impatient to begin before his re-election bid. They also say it laid the groundwork for the chaos unfolding now in Kabul.

“Our secretary of state signed a surrender agreement with the Taliban,” Mr. Trump’s second national security adviser, H.R. McMaster, said of Mr. Pompeo in a podcast interview on Wednesday. “This collapse goes back to the capitulation agreement of 2020. The Taliban didn’t defeat us. We defeated ourselves.”

The photo of Mr. Pompeo resurfaced this week on social media as the Taliban asserted control of Afghanistan. Mr. Baradar is widely expected to become the head of a new Taliban government based in Kabul.

In an interview with CNN on Wednesday, former Defense Secretary Mark T. Esper said that while President Biden “owns” the ultimate outcome in Afghanistan, Mr. Trump had earlier “undermined” the agreement through his barely disguised impatience to exit the country with little apparent regard for the consequences.

As the United States and other countries accelerate efforts to get Afghan allies out of the country, Afghan journalists employed by foreign news organizations are facing a more perilous route to safety from the Taliban, and some have been killed.

Despite assurances of amnesty by the regime, a growing number of reports indicate that Taliban are searching for Afghan reporters and in some cases targeting them or members or their families.

The German public broadcaster Deutsche Welle reported on Thursday that Taliban soldiers who were searching for one of their reporters had killed one member of his family and severely injured another. Taliban fighters also went house-to-house in western Afghanistan to search for two other reporters employed by the agency, it said.

“The Taliban are obviously conducting organized searches for journalists in Kabul and provinces,” the director of Deutsche Welle, Peter Limbourg, said in a statement. “Time is running out.”

The broadcaster, along with several other leading German media outlets, urged Chancellor Angela Merkel’s government to help them secure passage out of Afghanistan for its employees and their families.

“This letter is a cry for help,” the outlets wrote in an open letter this week, pleading for assistance in getting local Afghan staff members and their families out and securing visas for them. “The lives of our local staff are in acute danger.”

Last week, Amdullah Hamdard, 33, who learned English as a teenager and translated for U.S. Special Forces — they gave him the nickname “Huggy Bear” — had spent the last four years working with Die Zeit newspaper. He was murdered by Taliban fighters on the street near his home in Jalalabad, the paper reported.

In recent days, the publishers of The New York Times, The Wall Street Journal and The Washington Post banded together on evacuation efforts for staff members and their families. Security personnel and editors shared information on morning calls. The publishers called on the Biden administration to help facilitate the passage of their Afghan colleagues, and discussions ensued with officials at the White House, the Pentagon and the State Department.

This week, the first local employees of the three organizations flew out of the country after days of delays. For a group of 128 people from The Times, a breakthrough came when Qatar, a country with ties to both Afghanistan and the United States, agreed to help get them to safety.

Zabihullah Mujahid, the Taliban’s chief spokesman, told a gathering of reporters on Tuesday that media outlets “can continue to be free and independent,” although he that added “Islamic values should be taken into account.”

But on Thursday, Taliban fighters beat two Afghan journalists while violently dispersing a protest in the eastern city of Jalalabad.

The Committee to Protect Journalists, a New York-based watchdog group, noted other attacks against journalists in recent days, including the fatal shooting on Aug. 9 of a radio station manager in Kabul, and the kidnapping of a reporter in Helmand Province. Afghan press freedom groups blamed the Taliban for both incidents.

“The Taliban must cease searching the homes of journalists, commit to ending the use of violence against them, and allow them to operate freely and without interference,” the committee’s coordinator in Asia, Steven Butler, said in a statement.

An American journalist, Wesley Morgan, tweeted this week that the Taliban had searched the house of an Afghan interpreter he worked with. The interpreter, who was not at home, watched the search unfold on security footage sent to an app on his phone, Mr. Morgan said.

The director general of UNESCO, Audrey Azoulay, called on the Taliban to uphold their promises of protecting a free press, and the journalists who cover it. The organization has helped develop Afghanistan’s media over the past 20 years, including journalism education and gender-sensitive reporting.

“UNESCO urges that the important progress made should not be undone and in particular that women journalists must be able to continue their crucial work,” Ms. Azoulay said.

A member of Afghanistan’s national youth soccer team was among the people who were killed as they tried desperately to cling to a U.S. military plane evacuating people from Kabul this week, the country’s official sports federation said on Thursday.

His name was Zaki Anwari, and he was 17.

On Monday, a crowd of Afghans surged onto the tarmac of the international airport in the frantic scramble to escape a country newly overrun by the Taliban. In a scene that shocked the world, and in just one wrenching moment encapsulated the chaos of America’s exit from Afghanistan, some of them chased aircraft carrying Americans and tried to climb onto their sides, wings and wheels.

The young soccer player was among them, the federation said.

“Anwari was one of hundreds of young people who wanted to leave the country and, in an incident, fell off an American military plane and died,” the group said in a statement on Facebook.

The sports community of Afghanistan was in grief, the statement said. It wished Zaki a place in heaven and offered a prayer that God grant his family, friends and teammates peace and patience as they mourn.

The federation posted photos of Zaki wearing his team’s red jersey — he was No. 10 — and standing on a soccer field. Another photo showed him in a suit and tie. Beside them were photos of an airborne U.S. military plane with what appeared to be a falling body and a single red rose.

Video taken on Monday showed at least two bodies dropping to the ground from an airplane shortly after it took off. The Pentagon confirmed that two people had died falling from the plane, and body parts were also discovered in the landing gear of the aircraft after it landed in Qatar.

In a telephone interview on Thursday from Kabul, Aref Peyman, the head of media relations for the sports federation and for Afghanistan’s Olympic Committee, confirmed Zaki’s death.

Mr. Peyman said Zaki had come from a low-income family in Kabul and had worked hard to achieve his dream of being on the national soccer team while also attending school.

“He was kind and patient, but like so many of our young people he saw the arrival of the Taliban as the end of his dreams and sports opportunities,” Mr. Peyman said. “He had no hope and wanted a better life.”

Many Afghans took to social media to voice shock and anger.

“Shame on the Taliban,” wrote Marzieh Zal on the federation’s Facebook page.

“Rest in peace dear Zaki, I cannot believe you are not with us anymore,” wrote Mohammad Sharif Ahmadi in another post.

The rapid collapse of Afghanistan to Taliban control set off panic among many Afghans, including athletes, who feared that a return of extremist religious rule would bring about the end of their careers and other opportunities.

One Olympic athlete, the sprinter Kamia Yousufi, 25, who carried Afghanistan’s flag at the opening ceremony in Tokyo, has since fled to Iran, media reports said. Mr. Peyman confirmed those reports.

President Biden has come under sharp criticism for how the U.S. military has withdrawn from Afghanistan after a 20-year occupation. Mr. Biden has defended his handling of the exit. In an ABC News interview, he was also asked about the people who died clinging onto the plane and dismissed the question.

“That was four days ago, five days ago,” he said.

Recognition of a revolutionary authority is never a simple question. After the Bolsheviks took power in Russia in 1917, it was years before its newly established Soviet Union was recognized by Western nations. The United States refused recognition until 1933.

A similar question arises now in Kabul. The Taliban have seized power and have announced that Afghanistan should again be called the Islamic Emirate of Afghanistan, as it was when the Taliban last ruled the country in the 1990s.

But it has not yet formed a government, and some hope that any government that emerges in fragmented Afghanistan will be more broadly based than just the Taliban itself.

As a rule, governments talk to other governments, and sooner or later recognize them. For now, however, when it comes to Afghanistan, Western countries are holding off.

The question of recognition is expected to come up when Britain and the United States host a virtual meeting of the leaders of the Group of 7 countries, which is expected to take place early next week. On Thursday, G7 foreign ministers held a videoconference to prepare the ground for their leaders, with the crisis in Afghanistan the main topic, and called for the Taliban to respect human rights and protect civilians.

On the ground in Kabul, diplomats and military officers are talking to the Taliban on practical matters — about the airport, about trying to get safe passage to the airport for people who worked with Westerners. And the United Nations and some other nongovernmental organizations are continuing to work in Afghanistan, though the U.N. temporarily moved some of its staff.

But then there is the question of aid.

The United States has gotten the International Monetary Fund to suspend payment of about $370 million set to go to Afghanistan on Aug. 23. The fund cited the “lack of clarity within the international community” over recognizing a government in Afghanistan.

The European Union is also suspending development aid “until we clarify the situation” with Taliban leaders, its foreign policy chief, Josep Borrell Fontelles, said on Tuesday after a meeting of E.U. foreign ministers. Germany has also suspended aid payments.

The European Commission has pledged about €1.2 billion in development assistance for Afghanistan for the 2021-24 period, and member states have individually promised more. Britain, for instance, says it wants to double its humanitarian aid to Afghanistan to 280 million pounds a year, mostly channeled through U.N. agencies.

Mr. Borrell said similarly that “humanitarian help will continue, and maybe we will have an increase,” given the number of displaced Afghans, an ongoing drought and the impact of the coronavirus pandemic.

“The Taliban have won the war,’’ he said. “So we will have to talk with them in order to engage in a dialogue as soon as necessary to prevent a humanitarian and a potential migratory disaster.”

Talks would also focus, Mr. Borrell said, “on the means to prevent a return of a foreign terrorist presence in Afghanistan.’’

But he insisted that such discussions would be only on pragmatic issues, and that dialogue did not imply formal recognition of the new regime.

“We will deal with the Afghan authorities such as they are, at the same time remaining naturally vigilant of the respect of international obligations,” he said.

The Taliban have pledged that women in Afghanistan will have rights “within the bounds of Islamic law,” or Shariah, under their newly established rule. But it is not clear what that will mean.

Shariah leaves considerable room for interpretation. When the Taliban ruled Afghanistan in the past, they imposed a strict one, barring women from working outside the home or leaving the house without a male guardian, eliminating schooling for girls, and publicly flogging people who violated the group’s morality code.

The insurgents have not yet said how they intend to apply it now. But millions of Afghan women fear a return to the past ways.

Here are the basics of what to know about Shariah and how it could factor into the Taliban’s treatment of women.

What is Shariah?

Shariah is based on the Quran, stories of the Prophet Muhammad’s life and the rulings of religious scholars, forming the moral and legal framework of Islam. The Quran details a path to a moral life, but not a specific set of laws.

One interpretation of Shariah could afford women extensive rights, while another could leave women with few. Critics have said that some of the Taliban restrictions on women under the guise of Islamic law actually went beyond the bounds of Shariah.

The interpretations of Shariah are a matter of debate across the Muslim world, and all groups and governments that base their legal systems on Shariah have done so differently. When the Taliban say they are instituting Shariah law, that doesn’t mean they are doing so in ways that Islamic scholars or other Islamic authorities would agree with.

What does Shariah prescribe?

Shariah lists some specific crimes, such as theft and adultery, and punishments if accusations meet a standard of proof. It also offers moral and spiritual guidance, such as when and how to pray, or how to marry and divorce.

It does not forbid women to leave home without a male escort or bar them from working in most jobs.

How have the Taliban previously interpreted Shariah?

When the Taliban controlled Afghanistan from 1996 to 2001, they banned television and most musical instruments. They established a department for the Promotion of Virtue and the Prevention of Vice based on a Saudi model.

Restrictions on behavior, dress and movement were enforced by the morality police officers who drove around in pickup trucks, publicly humiliating and whipping women who did not adhere to their rules. In 1996, a woman in Kabul had the end of her thumb cut off for wearing nail polish, according to Amnesty International.

Women accused of adultery were stoned to death.

What might this mean for women now?

Experts have been scanning Taliban leaders’ recent behavior for clues as to whether their treatment of women will change.

When a senior Taliban official gave an interview to a female television journalist in Kabul this week, it was part of a broader campaign by the group to present a more moderate face to the world, and within Afghanistan.

But hours later, a prominent anchorwoman on state television said that the Taliban had suspended her and other women who worked there indefinitely.

A Taliban spokesman said that women would be allowed to work and study, and another official has said that women should participate in government — signaling a possible break with past practices.

But outside Kabul, some women have been told not to leave home without a male relative escorting them and the Taliban have prevented women from entering at least one university. They have also shut down some women’s clinics and schools for girls.

Hosna Jalil, the former deputy minister for women’s affairs in Afghanistan, told Deutsche Welle, a network in Germany, that she had little faith the Taliban would interpret Shariah differently now.

“​​Shariah law for them meant lack of access to education, restricted access to health services, no access to justice, no shelter, no food security, no employment, literally nothing,” she said.

Thousands of Afghan security force members have managed to make it to other countries over the past few weeks as the Taliban rapidly seized the country. Others negotiated surrenders and went back to their homes — and some kept their weapons and joined the winning side.

They were all part of the sudden atomization of the national security forces that the United States and its allies spent tens of billions of dollars to arm, train and stand against the Taliban, a two-decade effort at institution-building that vanished in just a few days.

But tens of thousands of other Afghan soldiers, commandos and spies who fought to the end have been left behind.

They are now on the run, hiding and hunted by the Taliban.

“There’s no way out,” Farid, an Afghan commando, said in a text message to an American soldier who had fought with him. He said he was hiding in the mountains of eastern Afghanistan, trapped after the regular army units surrendered around him. “I am praying to be saved.”

Accounts of the Taliban searching for people they believe worked with and fought alongside U.S. and NATO forces are beginning to trickle out. The militants are threatening to arrest or punish family members if they cannot find the people they are seeking.