American troops pulled out of their main military base in Afghanistan on Friday, a U.S. defence official said, under an agreement with the Taliban allowing for the withdrawal of all U.S. forces from the country after a two-decade war.

“All American soldiers and members of NATO forces have left the Bagram airbase,” said the senior U.S. security official on condition of anonymity.

The U.S. military has coordinated its air war and logistical support for its Afghan mission from the Bagram airbase, about 60 km (40 miles) north of Kabul, and the withdrawal of the forces symbolises the end of the U.S. military involvement in the country.

The base is being handed over to the Afghan government as its armed forces face a surging war with the Taliban and questions swirl about their prospects.

An Afghan official said the base would be officially handed over to the government at a ceremony on Saturday.

The U.S. defence official said General Austin Miller, the top U.S.commander in Afghanistan “still retains all the capabilities and authorities to protect the force” that are stationed in the capital, Kabul.

Two other U.S. security officials said this week the majority of U.S. military personnel would most likely be gone by July 4, with a residual force remaining to protect the embassy.

Last month, U.S. President Joe Biden told his Afghan counterpart, Ashraf Ghani, that “Afghans are going to have to decide their future, what they want”.

Ghani said his job was now to “manage the consequences” of the U.S. withdrawal.

The agreement with the Taliban on the U.S. pull-out was struck under the administration of President Donald Trump.

In exchange for the U.S. withdrawal, the Taliban, fighting to expel foreign forces and oust the U.S.-backed government, have vowed to prevent any international terrorism from Afghan soil.

They also made a commitment to enter into talks with their Afghan rivals but little progress has been made in negotiations.