Biden is the fourth US president to preside over the war in Afghanistan, which began in 2001, soon after Al Qaeda terrorists based in Afghanistan attacked the twin-towers in New York. 

In his speech to the nation, Biden, observing that the US went to Afghanistan because of a horrific attack that happened 20 years ago, said that he "cannot explain" why the US should remain there in 2021. 

"Rather than return to war with the Taliban, we have to focus on the challenges that will determine our standing and reach today and into the years to come," Biden said. 

A day earlier, the White House said that Biden has decided to withdraw all American troops out of war-torn Afghanistan by September 11 this year, the 20th anniversary of the 2001 terrorist attack on the twin towers in New York. 

"We cannot continue the cycle of extending or expanding our military presence in Afghanistan hoping to create the ideal conditions for our withdrawal, expecting a different result,” Biden said. 

"I am now the fourth American president to preside over an American troop presence in Afghanistan. Two Republicans. Two Democrats. I will not pass this responsibility to a fifth. 

"After consulting closely with our Allies and partners, with our military leaders and intelligence professionals, with our diplomats and development experts, and with Congress and the Vice President, I have concluded that: It is time to end America’s longest war. It is time for American troops to come home," the President said. 

He said that America will “not conduct a hasty rush to the exit." 

While the US will not stay involved in Afghanistan militarily, its diplomatic and humanitarian work will continue… America will continue to support the Government of Afghanistan, he said. 

"We will keep providing assistance to the Afghan National Defence and Security Forces. Along with our partners, we are training and equipping nearly 300,000 personnel. And they continue to fight valiantly on behalf of their country and defend the Afghan people, at great cost. 

"We will support peace talks between the Government of Afghanistan and the Taliban, facilitated by the United Nations,” Biden said. 

The US and the Taliban signed a landmark deal in Doha on February 29, 2020 to bring lasting peace in war-torn Afghanistan and allow US troops to return home from America's longest war. 

Under the US-Taliban pact signed in Doha, the US agreed to withdraw all its soldiers from Afghanistan in 14 months. 

Since the US-led invasion that ousted the Taliban after the September 11, 2001 attacks, America has spent more than USD 1 trillion in fighting and rebuilding in Afghanistan. 

About 2,400 US soldiers have been killed, along with tens of thousands of Afghan troops, Taliban insurgents and Afghan civilians.