America has ended its longest war in Afghanistan, President Joe Biden announced on Tuesday, hours after the final US evacuation plane flew out of Kabul airport amidst celebratory gunfire from the Taliban, leaving the country in disarray and its future uncertain under the rule of hardline Islamist militants.

The last plane carrying US forces left Afghanistan on Monday around midnight, a day ahead of schedule, ending a 20-year war that left nearly 2,500 American troops dead and spanned four presidencies.

The C17 aircraft's departure from Kabul's international airport was the final chapter in a contentious military effort, which eventually saw the US handing Afghanistan back to the very Islamist militants it sought to root out when American troops entered the country in 2001.

Celebratory gunfire and fireworks erupted across Kabul as Taliban fighters took control of the airport following the withdrawal, proclaiming “full independence” for Afghanistan.

“Now, our 20-year military presence in Afghanistan has ended,” Biden said, thanking armed forces for their execution of the dangerous retrograde from Afghanistan with no further loss of American lives.

“For now, I will report that it was the unanimous recommendation of the Joint Chiefs and of all of our commanders on the ground to end our airlift mission as planned.

“Their view was that ending our military mission was the best way to protect the lives of our troops, and secure the prospects of civilian departures for those who want to leave Afghanistan in the weeks and months ahead,” he said.

The president, who will address the nation later on Tuesday, said he has asked the Secretary of State to lead the continued coordination with US international partners to ensure safe passage for any American, Afghan partners and foreign nationals who want to leave Afghanistan.