A senior U.S. official said President Joe Biden is committed to the deadline, though European leaders had pressed for more time.
The Taliban warned Tuesday that the U.S. airlift from Afghanistan must end August 31, ramping up pressure on an already chaotic evacuation as new reports of rights abuses fueled concern about the fate of thousands of people still trying to flee the country.
A senior U.S. official said President Joe Biden is also committed to the deadline, though European leaders had pressed for more time. British Prime Minister Boris Johnson said the Group of Seven nations will not recognize a Taliban government unless the group guarantees people can leave the country if they wish, both before and after the August deadline.
The announcements set the stage for an endgame a day after the CIA director met with a top Taliban leader in Kabul. The extraordinary meeting reflected the gravity of the crisis and America's need to coordinate with the Taliban as it struggles to end a two-decade war against them.
Recent days have seen a flurry of efforts to speed the evacuation at Kabul's airport, where scenes of desperation have highlighted both the disarray of the U.S. pullout and fears that the Taliban will resort to the brutal tactics they used when they last ruled Afghanistan.
Taliban spokesman Zabihullah Mujahid told a news conference the U.S. must stick to its self-imposed deadline for withdrawing all troops, saying "after that we won't let Afghans be taken out" on evacuation flights.
He also said the Taliban would bar Afghans from accessing roads leading to the airport, while allowing foreigners to pass through in order to prevent large crowds from massing outside the facility. It was not immediately clear if they would stop Afghans who are escorted by foreigners or in the process of being evacuated by Western nations.
For now, the U.S. military coordinates all air traffic in and out of the Kabul airport, where American and other NATO troops are helping people board evacuation planes. There have been no commercial flights outside of the evacuation effort since Aug. 16, the day after the capital fell to the Taliban and sealed their control of the country.
The Taliban will take over security at the airport after the planned U.S. pullout, Mujahid said. It's unclear when commercial flights would resume, putting pressure on the current evacuation efforts to get as many people out as possible.
About 21,600 people were flown out in the 24-hour period that ended early Tuesday, the White House said — reflecting a significant increase as the airlift accelerates.
Meanwhile, a U.S. official said CIA Director William Burns and Taliban leader Mullah Abdul Ghani Baradar met — an extraordinary moment for the U.S. agency, which for two decades targeted the Taliban in paramilitary operations. It was not clear what exactly they discussed.
The CIA partnered with Pakistani forces to arrest Baradar in 2010, and he spent eight years in a Pakistani prison before the Trump administration persuaded Pakistan to release him in 2018 ahead of U.S. peace talks with the Taliban.
The Washington Post first reported Burns' meeting with Baradar. A U.S. official confirmed the report on condition of anonymity because the official was not authorized to speak publicly. Mujahid said he was not aware of any such meeting but did not deny that it took place.
Mujahid, meanwhile, pushed back on the idea that Afghans need to flee, arguing that the Taliban have brought peace and security to the country. He said the main problem was the chaos at the airport, and he accused the U.S. of luring away engineers, doctors and other professionals on which the country relies.
Earlier, U.N. human rights chief Michelle Bachelet said she had credible reports of "summary executions" of civilians and former security forces who were no longer fighting, the recruitment of child soldiers and restrictions on the rights of women to move around freely and of girls to go to school.
She did not specify the timing or source of her reports.
It has been difficult to determine how widespread abuses might be and whether they contradict the Taliban's public statements or reflect disunity in its ranks.
But the reports have helped fuel the crush of people racing to leave the country, fearing that they signal a return to the Taliban's previous rule. From 1996 until the 2001 U.S.-led invasion, the Taliban largely confined women to their homes, banned television and music, chopped off the hands of suspected thieves and held public executions.
"At this critical moment, the people of Afghanistan look to the Human Rights Council to defend and protect their rights," Bachelet said. "I urge this council to take bold and vigorous action, commensurate with the gravity of this crisis, by establishing a dedicated mechanism to closely monitor the evolving human rights situation in Afghanistan."
By "mechanism," Bachelet was referring to the possibility that the council might appoint a commission of inquiry, special rapporteur or fact-finding mission.
Reflecting concerns about abuses, European leaders had hoped the U.S. would consider delaying its withdrawal to allow for more evacuations. The Taliban have said Aug. 31 is a "red line" and that any presence beyond then would "provoke a reaction."
German Foreign Minister Heiko Maas said the majority of local staff who worked for his country in Afghanistan have not yet gotten out and called Tuesday's meeting "very important" for discussing international access to the Kabul airport beyond the end of August. Britain's defense minister separately has called the deadline a "mistake."
But Britain's Johnson acknowledged defeat on changing Biden's course after a G-7 meeting.
"We will go on right up until the last moment that we can," he said. "But you've heard what the president of the United States has had to say, you've heard what the Taliban have said."
Biden made his decision to stick with the deadline after consultation with his national security team, an official said, speaking on condition of anonymity to discuss a decision not yet publicly announced.
Tragic scenes at the airport have transfixed the world. Afghans poured onto the tarmac last week and some clung to a U.S. military transport plane as it took off, later plunging to their deaths. At least seven people died that day, and another seven died Sunday in a panicked stampede. An Afghan solider was killed Monday in a gunfight.