Several hundred American citizens remain if Afghanistan after the US completed its withdrawal from the country yesterday, Pentagon press secretary John Kirby confirmed Tuesday.

“We believe we got the vast, vast majority of American citizens out, something to the tune of 6,000 of them,” Kirby told MSNBC’s Willie Geist. “And we think it’s probably in the low hundreds that are still there. And there were also several hundred others that didn’t want to leave.”

He added that the US did not have an "exact figure" on the number of Americans who remain in Afghanistan.

The last C-17 plane departed Kabul's international airport just before midnight Monday night ahead of US President Joe Biden's August 31 deadline for completing the withdrawal from Afghanistan.

This concluded the US presence in Afghanistan, almost 20 years after the September 11, 2001, terrorist attacks.

Footage posted on social media after the announcement showed Taliban fighters celebrating the US withdrawal by firing in the air.

Biden is expected to address the nation on the completed withdrawal later today.

US Secretary of State Antony Blinken said that America expects the Taliban to live up to its commitments now that US troops have pulled out of Afghanistan.

"Our troops have departed Afghanistan. A new chapter of America's engagement with Afghanistan has begun,” Blinken said, according to AFP.

"It's one in which we will lead with our diplomacy. The military mission is over; a new diplomatic mission has begun," he added.

Earlier on Monday, US President Joe Biden urged the Taliban to allow freedom of travel to people wishing to leave the country.

“The Taliban has made commitments on safe passage and the world will hold them to their commitments. It will include ongoing diplomacy in Afghanistan and coordination with partners in the region to reopen the airport allowing for continued departure for those who want to leave and delivery of humanitarian assistance to the people of Afghanistan,” he said in a statement.