Since the Taliban pushed their attack on Kabul, US officials say they have evacuated around 13000 individuals, causing chaos at the capital's airports as Afghans and Americans tried desperately to board aircraft out of the beleaguered country.

As he confronts a barrage of criticism for his management of the US departure, US President Biden spoke on Friday about the effort to evacuate American people and Afghan friends from Afghanistan in the face of the Taliban's takeover.

"This is one of the largest, most difficult airlifts in history," Biden said in a televised address from the White House. "I cannot promise what the final outcome will be."

The president said US forces have airlifted 13,000 people out of Afghanistan since August 14, and 18,000 since July, with thousands more evacuated on private charter flights "facilitated by the US government."

Here are the highlights of the speech of US President Joe Biden:

The Kabul evacuation was among 'largest and most difficult airlifts in history.

US has airlifted 13,000 people out of Kabul since Aug 14.

US allies do not raise the 'question of our credibility'.

Cannot guarantee 'final outcome' of risky Kabul evacuation.

According to the Pentagon, 22,000 Afghan Special Immigrant Visa (SIV) candidates would be transferred to the United States and accommodated at three military sites.

Officials have recognised, however, that this amount may climb, and relief organisations and some politicians have called for it to be significantly raised.