The Taliban has effectively sealed its control of Afghanistan after the nation’s president fled the capital and announced the insurgents were now responsible for citizens.

Afghan President Ashraf Ghani has taken to social media to confirm his departure from Kabul, saying that numerous countrymen would have been martyred and the city destroyed if he had stayed.

“I was faced with a difficult choice today: wait to face armed Taliban entering the Presidential Palace or exit the country,” Mr Ghani wrote in a statement posted to Facebook.

“I chose to exit so I could prevent this bloodshed.”

He said the Taliban had achieved their success by using armed force and were now responsible for protecting the lives, property and honour of citizens, noting that “a lot of people and groups are afraid and uncertain of the future.”

“They are now facing a new historical test; either they will protect the name and honour of Afghanistan or they will prioritise other places and networks,” Mr Ghani wrote.

The president reportedly fled with his wife, his chief of staff and his national security advisor to Tashkent.

Meanwhile, the Taliban has fanned out across the capital, and an official with the militant group said it would soon announce the creation of the Islamic Emirate of Afghanistan from the presidential palace in Kabul.

That was the name of the country under Taliban rule before the militants were ousted by US-led forces after the 9/11 attacks.

The Al-Jazeera news network later aired footage showing a group of Taliban fighters inside the presidential palace.

The city was gripped by panic, with helicopters racing overhead throughout the day to evacuate personnel from the US embassy.

Smoke rose near the compound as staff destroyed important documents. Several other Western missions also prepared to pull their people out.

Afghans fearing that the Taliban could reimpose the kind of brutal rule that all but eliminated women’s rights rushed to leave the country. The desperately poor – who had left homes in the countryside for the presumed safety of the capital – remained in parks and open spaces throughout the city.

As night fell, Taliban fighters deployed across Kabul, taking over abandoned police posts and pledging to maintain law and order during the transition.

Residents reported looting in parts of the city, including in the upscale diplomatic district, and messages circulating on social media advised people to stay inside and lock their gates.

The Taliban has seized nearly all of Afghanistan in just over a week, despite the billions of dollars spent by the US and NATO over nearly two decades to build up Afghan security forces.

Afghan security forces were patrolling the capital, Kabul, before the Taliban breached the city. Photo: Getty

The fall of Kabul marks the final chapter of America’s longest war, which began after the September 11, 2001, terror attacks masterminded by al-Qaida’s Osama bin Laden, then harboured by the Taliban government.

Afghanistan’s acting defence minister, Bismillah Khan Mohammadi, didn’t hold back his criticism of the fleeing president.

“They tied our hands from behind and sold the country,” he wrote on Twitter. “Curse Ghani and his gang.”

The Taliban earlier insisted their fighters wouldn’t enter people’s homes or interfere with businesses and said they’d offer an “amnesty” to those who worked with the Afghan government or foreign forces.

But there have been reports of revenge killings and other brutal tactics in areas of the country the Taliban have seized in recent days – and the reports of gunfire at the airport raised the spectre of more violence.

One female journalist, weeping, sent voice messages to colleagues after armed men entered her apartment building and banged on her door.

“What should I do? Should I call the police or Taliban?” Getee Azami cried. It wasn’t clear what happened to her after that.

-with AAP