US Secretary of State Antony Blinken said Tuesday that the Taliban had recommitted to letting Afghans leave, as he held talks in Qatar aimed at speeding up evacuations.

US President Joe Biden has faced mounting pressure as activists said that several hundred people, also including Americans, had been prevented for a week from flying out of an airport in the northern city of Mazar-i-Sharif.

But Blinken said that the United States had been in touch again Tuesday with the Taliban and believed they were cooperating -- a key test as the United States weighs whether to work with the next government in Afghanistan.

"We are not aware of anyone being held on an aircraft or any hostage-like situation in Mazar-i-Sharif," Blinken told a news conference in Doha where he and Defense Secretary Lloyd Austin met their Qatari opposite numbers.

The Taliban told the United States that "they will let people with travel documents freely depart," Blinken said.

US Secretary of State Antony Blinken (2nd-R) and Secretary of Defense Lloyd Austin (L) with Qatari Deputy Prime Minister and Foreign Minister Mohammed bin Abdulrahman Al Thani (R) and Qatari Deputy Prime Minister and Defense Minister Dr. Khalid bin Mohamm
US Secretary of State Antony Blinken (2nd-R) and Secretary of Defense Lloyd Austin (L) with Qatari Deputy Prime Minister and Foreign Minister Mohammed bin Abdulrahman Al Thani (R) and Qatari Deputy Prime Minister and Defense Minister Dr. Khalid bin Mohammed Al-Attiyah (2nd-L). POOL / Olivier DOULIERY

"The entire international community is looking to the Taliban to uphold that commitment," Blinken said, referring to a UN Security Council resolution that urged safe passage.

Qatar, a US ally that has emerged as a key player both in evacuations and diplomacy on Afghanistan, said it was working to restore the Kabul airport which has been in disarray since the chaotic end of the 20-year US war.

A reopening would allow both a resumption of evacuations, if the Taliban follow through on commitments, and the shipment of badly needed humanitarian assistance.

US Secretary of State Antony Blinken tours a processing centre for Afghan refugees at al-Udeid Air Base in the Qatari capital Doha
US Secretary of State Antony Blinken tours a processing centre for Afghan refugees at al-Udeid Air Base in the Qatari capital Doha POOL / Olivier DOULIERY

Blinken and Austin voiced appreciation in a dinner Monday with Qatar's ruler Emir Sheikh Tamim bin Hamad Al-Thani.

On Tuesday Blinken toured the Al-Udeid airbase outside of Doha, where nearly half of the more than 120,000 people airlifted out of Afghanistan have transited.

The two cabinet members met privately with five Afghans who had worked for the United States and fled for fear of retribution, with Blinken voicing empathy for their journey.

"We're going to do right by you," said Blinken, the stepson of a Holocaust survivor and a longtime advocate for refugees.

He toured an aircraft hangar that had been converted into an air-conditioned processing hub in the hot desert sun, with more than 200 green cots -- now empty -- set up for Afghans, and soldiers staffing a table to distribute baby formula and diapers.

US Secretary of State Antony Blinken (left) and French Foreign Affairs Minister Jean-Yves Le Drian speak at a news conference at the Quai d'Orsay, the French foreign ministry
US Secretary of State Antony Blinken (left) and French Foreign Affairs Minister Jean-Yves Le Drian speak at a news conference at the Quai d'Orsay, the French foreign ministry POOL / Andrew Harnik

"I'm grateful for what you've done, your country is proud of you, the president of the United States is proud of you," Austin told assembled US soldiers and civilians at the base.

Doha is the Taliban's international diplomatic base although Blinken's aides said he has no plans to meet them as Washington instead waits to judge the group's actions in power to determine the level of engagement.

The United States on Monday facilitated the evacuation of four Americans from the same family by land out of Afghanistan, the first departures arranged by Washington since the military pullout.

A State Department official said the Taliban were aware of the operation and did not interfere.

But non-governmental organisations say that some 600 to 1,300 people -- including girls and US citizens -- are stuck at the airport in Mazar-i-Sharif.

Blinken said that the Taliban had not blocked people with valid travel documents but that not all passengers on charter flights had papers.

He said there were inevitable obstacles to charter flights as the United States does not have personnel on the ground.

"We don't have the means to verify the accuracy of manifests, the identity of passengers aboard these planes, aviation security protocols, or where they plan to land -- among other issues. These are real concerns," he said.

"We are engaging as we speak to resolve these issues."

US officials say they no longer control the airspace in Afghanistan and that the main airport in Kabul, which the US military seized in August for evacuations, is in disrepair.

Qatari technical teams have deployed to Kabul to assess the viability of the airport and begin to prepare it for a return to operation to allow evacuations and the arrival of badly needed humanitarian supplies.

Austin acknowledged that the withdrawal created obstacles but said the United States was committed to stopping threats from Afghanistan.

"There is no question it (the withdrawal) will make it more difficult to identify and engage threats that emanate from the region," Austin said.