The Taliban declared the war in Afghanistan was over after terrorists took control of the presidential palace in Kabul as US-led forces departed and Western nations scrambled on Monday to evacuate their citizens.

President Ashraf Ghani fled the country on Sunday as the Islamist terrorists entered the city, saying he wanted to avoid bloodshed, while hundreds of Afghans desperate to leave flooded Kabul airport.

"Today is a great day for the Afghan people and the mujahideen. They have witnessed the fruits of their efforts and their sacrifices for 20 years," Mohammad Naeem, the spokesman for the Taliban's political office, told Al Jazeera TV.

"Thanks to God, the war is over in the country."

Naeem said the type and form of the new regime in Afghanistan would be made clear soon, adding the Taliban did not want to live in isolation and calling for peaceful international relations.

"We have reached what we were seeking, which is the freedom of our country and the independence of our people," he said. "We will not allow anyone to use our lands to target anyone, and we do not want to harm others."

In Washington, opponents of President Joe Biden's decision to end America's longest war, launched after the Sept. 11, 2001, attacks, said the chaos was caused by a failure of leadership.

American diplomats were flown by helicopter to the airport from their embassy in the fortified Wazir Akbar Khan district as Afghan forces, trained for years and equipped by the United States and others at a cost of billions of dollars, melted away.

A US State Department spokesperson said early on Monday that almost all embassy personnel, including Ambassador Ross Wilson, were at the airport and the American flag had been lowered and removed from the embassy compound.

At Kabul airport, hundreds of Afghans waited for flights, some dragging luggage across runways in the dark, while women and children slept near security corridors.

A source at the airport said some scuffles broke out among people unable to get a place as departures were halted.

Local television 1TV reported that multiple explosions were heard in the capital after dark, but the city was largely quiet during the day on Sunday.

Aid group Emergency said 80 wounded people had been brought to its hospital in Kabul, which was at capacity, and that it was only admitting people with life-threatening injuries.

In a Facebook post, Ghani said he had left the country to avoid clashes with the Taliban that would endanger millions of residents of Kabul.

He did not say where he was and it was not clear where he was headed or how exactly power would be transferred following the Taliban's lightning sweep across Afghanistan.

Al Jazeera earlier showed footage of what it said were Taliban commanders in the presidential palace with dozens of armed fighters.

Some local social media users in Kabul branded Ghani a coward for leaving them in chaos. A tweet from the verified account of the Afghan Embassy in India said: "We are all banging our heads in shame."