The US is scrambling to speed up its removal of embassy staff from Kabul as Taliban forces surround the Afghan capital.
It hopes to have its staff out of Kabul within 72 hours, CNN reported.
“That is our number-one mission,” US Secretary of State Antony Blinken told the channel’s Jake Tapper. “That's what we're working on with a whole-government effort led by the State Department right now.”
Mr Blinken refused to put a timetable on those efforts. But it came as the US sent another 1,000 troops back to Afghanistan to aid the process.
Speaking to NBC's Meet the Press on Sunday Mr Blinken acknowledged the US would no longer operate out of its current embassy in Kabul. "We're going to have our core diplomatic presence and in effect an embassy at a location at the airport," he said.
Republican politicians have slammed the Joe Biden administration for the rapidly deteriorating situation. The Taliban entered the capital after taking most of Afghanistan as the US withdrew its forces after nearly 20 years in the country.
Michael McCaul, a Republican on the Foreign Affairs Committee, said the fall may be worse than what transpired in Saigon after the US withdrew from Vietnam in 1975.
“This is an unmitigated disaster of epic proportions,” he said on CNN. “This is going to be a stain on this president and his presidency. And I think he's going to have blood on his hands for what they did.”
Mr Blinken defended the president’s decision to push forward with the military withdrawal despite the threat posed by the Taliban.
“That status quo was not sustainable. Like it or not, there was an agreement that the forces would come out on May 1. Had we not begun that process ... and the Taliban saw, then we would have been back at war with the Taliban,” he said.
Mr Blinken acknowledged that the collapse of the Afghan military, which the US spent the better part of two decades building up and training, happened “more quickly than we anticipated”.
The hurried departure of US embassy staff in Kabul is happening without the watchful eye of an American ambassador in the country. The US has been without an ambassador to Afghanistan since January last year, when John Bass stepped down.
Mr Biden has yet to name a new top diplomat to Kabul.
Ross Wilson, a career diplomat who has served as US ambassador to Azerbaijan and Turkey, is currently the charge d’affaires in Kabul.