As the country's new Taliban rulers prepared to assume control of the airport, US soldiers were in the final stages of withdrawing from Kabul, bringing an end to two decades of costly participation in Afghanistan.

A Western security official told Reuters that just over 1,000 civilians remained at the airport on Sunday, waiting to be flown out before the military eventually leave.

"We want to ensure that every foreign civilian and those who are at risk are evacuated today. Forces will start flying out once this process is over," said the official, who is stationed at the airport.

President Joe Biden of the United States has stated that he will meet his timetable of withdrawing all US soldiers from Afghanistan by Tuesday. On Saturday, a US official told Reuters that just about 4,000 troops remained at the airport.