The United States is pressing the Taliban to let Afghans flee through the US-controlled airport as they have promised, after reports they have violated those assurances, Deputy Secretary of State Wendy Sherman said Wednesday.

"We have seen reports that the Taliban, contrary to their public statements and their commitments to our government, are blocking Afghans who wish to leave the country from reaching the airport," Sherman told reporters.

US diplomats in Doha and military officials in Kabul "are engaging directly with the Taliban to make clear that we expect them to allow all American citizens, all third-country nationals and all Afghans who wish to leave to do so safely and without harassment," she said.

Sherman said that the Taliban appeared to be honoring their commitment to allow US citizens to head to the airport.

But she said that the United States was looking for assurances on safe passage for "everybody who is trying to get to the airport."

"The Taliban are hoping to create a government in Afghanistan. They seek legitimacy. We are all watching their actions," she said.

The US military secured the airport to fly out US citizens and other vulnerable people after the Afghan government crumbled to the Taliban over the weekend.

Kabul's fall came a head of US President Joe Biden's August 31 deadline for the end of the two-decade US military mission.