Some criticized the State Department, which has sole authority to grant visas to former interpreters and other US military support staff and their families, for waiting more than two months to begin the process for Afghans in fear of their lives.

Videos posted on social networks showed scenes of panic and fear in Kabul, including crowds running next to a US military transport plane as it taxies to take off, with some trying to desperately cling to its sides.

"We warned them for months, for months" that the situation was urgent, said one military official, speaking on condition of anonymity.

"I am not angry, I am frustrated," another officer remarked. "The process could have been handled so differently."

Biden decided in mid-April that all US troops must be out of Afghanistan by September 11, though he later moved that date up to August 21.

The State Department however waited months to set up an ad hoc structure to get US allies to safety.

Another Pentagon official interviewed by AFP said that diplomats had tried to speed up the visa process -- but the process was too long and complicated under the circumstances.

The Biden administration assumed that the US embassy in Kabul would remain open and that the Afghan government would retain control of the country for months after the US withdrawal, he said.

- It's 'personal' -

As soon as Biden announced the withdrawal, the Pentagon said it was making preparations for a mass evacuation.

But by mid-June the administration still did not consider an evacuation necessary and favored the granting of special visas -- a process that can take up to two years.

It was only at the end of June that the White House raised the possibility of evacuating the Afghan interpreters before the end of the military withdrawal, and asked for the Pentagon's help.

A crisis cell was then set up to organize the reception of Afghan refugees on US bases as they waited for their visas to be issued.

Asked during a press briefing on Monday about the delay of more than two months between the announcement of the withdrawal and the creation of the crisis cell, its director Garry Reid stressed that the Pentagon could only act in "support of the State Department."

State Department spokesman Ned Price said that, when the administration realized that the situation was "quickly evolving," it launched what Operation Allied Refuge, which he described as "a gargantuan US effort not only to process, adjudicate and to grant visas to so-called Special Immigrants but to actually bring them to the United States with a massive airlift operation."

He said 2,000 Afghans have been brought to the US through the airlift so far.

The action group, Pentagon spokesman John Kirby said, got stood up in July.

"But you can go back to the spring and hear the Secretary (of Defense Lloyd Austin) himself talk about interpreters and translators and the sacred obligation that we know that we have to them," said Pentagon spokesman John Kirby.

"Everything that you're seeing in the last 48-72 hours is personal for everybody here at the Pentagon," Kirby added of the images coming out of Afghanistan.

"Many of us have spent time in Afghanistan over the years and feel a deep sense of connection to the current events," General Hank Taylor, the US military's chief of logistics, told the same news briefing.

But, he added, "we are focused on the safest evacuation of Americans and Afghans."