Calm returned to Kabul's international airport Tuesday after a chaotic day saw hundreds of Afghans fleeing the Taliban rush the runway and hang off a U.S. Air Force flight, with several plunging to the deaths in chaos that killed at least seven people.

The crowds came Monday while the Taliban enforced their rule over the capital of 5 million people after a lightning advance across the country that took just over a week to dethrone the country's Western-backed government. There were no major reports of abuses or fighting, but many residents stayed home and remained fearful after the insurgents' takeover saw prisons emptied and armories looted.

A resolute U.S. President Joe Biden later said he stood 'squarely behind' his decision to withdraw American forces and acknowledged the 'gut-wrenching' images unfolding in Kabul. Biden said he faced a choice between honoring a previously negotiated withdrawal agreement or sending thousands more troops back to begin a third decade of war.

'After 20 years, I've learned the hard way that there was never a good time to withdraw U.S. forces,' Biden said in a televised address from the White House.

Stefano Pontecorvo, NATO's senior civilian representative to Afghanistan, posted video online showing the runway empty with American troops on the tarmac. What appeared to be a military cargo plane could be seen in the distance from behind a chain-link fence in the footage.

The runway 'is open,' he wrote on Twitter. 'I see airplanes landing and taking off'.

Overnight, flight-tracking data showed a U.S. Marine Corps KC-130J Hercules plane at the airport and later taking off for Qatar, home to Al-Udeid Air Base and the U.S. military Central Command's forward headquarters. There were no other immediate flights seen in Afghan airspace, which has been taken over by the American military as commercial flights have been halted in the country.

Across Afghanistan, the International Committee of the Red Cross said thousands had been wounded in the fighting. Security forces and politicians handed over their provinces and bases without a fight, likely believing the two-decade Western experiment to remake Afghanistan would not survive the resurgent Taliban. The last American troops had planned to withdraw at the end of the month.

'The world is following events in Afghanistan with a heavy heart and deep disquiet about what lies ahead,' United Nations Secretary-General Antonio Guterres said.

Talks appeared to be continuing between the Taliban and several Afghan government officials, including former President Hamid Karzai and Abdullah Abdullah, who once headed the country's negotiating council. President Ashraf Ghani earlier fled the country amid the Taliban advance and his whereabouts remain unknown.

An official with direct knowledge of the talks, who spoke on condition of anonymity as he wasn't authorized to brief journalists, said senior Taliban leader Amir Khan Muttaqi had arrived in Kabul from Qatar. Muttaqi is a former higher education minister during the Taliban's last rule. Muttaqi had begun making contact with Afghan political leaders even before Ghani fled.