US President Joe Biden on Sunday said he will hold discussions with American military leaders to extend the August 31 deadline for ending his country's mission in Afghanistan.
"There are going to be discussions, I suspect, on how far along we are in the [evacuation] process,” Mr Biden said.
There has been speculation about the time it would take to bring home thousands of Americans still in Afghanistan.
But Mr Biden made it clear that such extension was not his preference.
“Our hope is that we will not have to extend,” he said.
Mr Biden reaffirmed that his "first priority in Kabul is getting American citizens out of the country as quickly and as safely as possible".
He estimated that his administration has flown out nearly 33,000 people from Afghanistan since July.
Mr Biden strongly defended his decision to withdraw from Afghanistan despite the government collapse in that country and the Taliban takeover.
"At the end of the day, if we didn't leave Afghanistan now, when do we leave? Another 10 years? Another five years? Another year?” he asked.
He stood by that judgment to end America's longest war despite a recent dip in his polling numbers.
Mr Biden called it an “absolutely correct in not deciding to send more women and men to war, for a war that in fact is no longer warranted".
He said he did not trust the Taliban – "I don't trust anybody" – but the militant group had "by and large" kept its commitment in allowing Americans to leave.
Earlier on Sunday, US National Security Adviser Jake Sullivan described the ISIS threat to Kabul airport in Afghanistan as “acute” and “persistent”.
Mr Sullivan said the US administration was prepared to use variety of tools to address it.
“The threat is real. It’s acute. It is persistent. And it is something we’re focused on with every tool in our arsenal,” he told CNN on Sunday.
Mr Sullivan said the US military had “a wide variety of capabilities they’re using to defend the airfield against a potential terrorist attack”.
“We’ll do everything we can as long as we’re on the ground to keep that from happening, but we are taking it absolutely deadly seriously,” he said.
Mr Sullivan defended Mr Biden’s comments on Friday, in which the president said that Al Qaeda “is gone” from Afghanistan.
“First of all, I reject that characterisation [of Mr Biden’s comments] with respect to Al Qaeda," he said.
"Right now, our intelligence community does not believe that Al Qaeda in Afghanistan represents a threat to the United States homeland."
Mr Sullivan estimated the number of American citizens still in Afghanistan to be in the thousands.
The US has now flown out nearly 30,000 people from Afghanistan and signed agreements with two dozen countries to assist in the process, Secretary of State Antony Blinken told Fox News on Sunday.
"The last 24 hours, about 8,000 people on about 60 flights evacuated from Kabul airport," Mr Blinken said.
It is accelerating its evacuation mission. On Sunday, US Secretary of Defence Lloyd Austin ordered the country’s commercial airlines to provide planes to help.
The order entails activating 18 planes, including three each from Atlas Air, Delta Air Lines, American Airlines and Omni Air, four from United Airlines and two from Hawaiian Airlines.
They would not enter Kabul airport but travel to third countries to which the US military has taken those who have left.