Washington, Aug 19 (IANS): US President Joe Biden said that he did not see a way to withdraw from Afghanistan without "chaos ensuing".

Biden, who is facing mounting criticism from the public over the chaotic evacuation, defended his decision to withdraw the US troops from Afghanistan while speaking to ABC News on Wednesday, reports Xinhua news agency.

Asked if the US drawdown could have been handled better, Biden replied: "No, I don't think it could have been handled in a way that ... but the idea that somehow, to have gotten out without chaos ensuing, I don't know how that happens."

"One of the things we didn't know is what the Taliban would do in terms of trying to keep people from getting out," he said.

"They're cooperating, letting American citizens get out... But we're having some more difficulty having those who helped us when we were in there."

He also said that the US military could extend its mission in Afghanistan beyond August 31 to evacuate Americans on the ground.

National Security Adviser Jake Sullivan said on Tuesday that the Taliban informed the US that they would provide safe passage of civilians to Kabul airport.

Deputy Secretary of State Wendy Sherman said on Wednesday that US military flights had evacuated over 2,000 people in the last 24 hours and nearly 5,000 people over the last several days.

The US Embassy in Afghanistan earlier in the day issued a security alert saying "the US Government cannot ensure safe passage to the Hamid Karzai International Airport".

According to media reports, up to 15,000 Americans still remain in Afghanistan.

At a Pentagon briefing on Wednesday, Secretary of Defense Lloyd Austin said about 4,500 US troops had arrived in Kabul, but their mission was to secure the airport.

"We don't have the capability to go out and collect up large numbers of people."

US troops on the ground had no hostile interaction with the Taliban, and the lines of communication with the insurgent commanders remain open, he said.

Austin said that the US military is working hard to get more people evacuated while noting "we're not close to where we want to be in terms of getting the numbers through".

The Pentagon said on Tuesday that it could have the capacity to evacuate as many as 5,000 to 9,000 per day at best effort.

Afghan President Mohammad Ashraf Ghani left the country on Sunday as the Taliban forces entered the capital of Kabul and took control of the presidential palace.

The United Arab Emirates Ministry of Foreign Affairs and International Cooperation confirmed on Wednesday that the country had welcomed Ghani and his family into the country "on humanitarian grounds".

"He is no longer a figure in Afghanistan," said Sherman when asked about US reaction to Ghani's whereabouts.