President Joe Biden is slated to address the nation from the White House Monday afternoon after the Taliban seized the presidential palace in the war-weary Afghan capital of Kabul over the weekend, a dramatic development that marks the apparent end to a 20-year American era in the country.

Biden’s remarks come one day after Taliban insurgents pushed their frontlines into Kabul after a succession of shocking battlefield reversals, spurred by the exodus of U.S. and coalition forces.

Afghan President Ashraf Ghani fled the country as Western nations rushed to evacuate embassies amid a deteriorating security situation.

The State Department confirmed Tuesday evening that all U.S. diplomatic staff at the embassy in Kabul had been safely transported to Kabul’s international airport.

In April, Biden ordered the Pentagon to withdraw U.S. troops from Afghanistan by Sept. 11, a decision he said was made in lockstep with NATO coalition forces.

Last week, Biden told reporters last week at the White House that he did not regret his decision to withdraw U.S. forces from Afghanistan, effectively ending America’s longest war.

“Look, we spent over a trillion dollars over 20 years, we trained and equipped with modern equipment over 300,000 Afghan forces,” Biden said on August 10.

“Afghan leaders have to come together,” the president added.

Two U.S. defense officials confirmed to NBC News that the Taliban also seized Bagram Air Base on Sunday, a development that comes less than two months after the U.S. military handed over the once-stalwart airbase to the Afghan National Security and Defense Force.

The Taliban began emptying out Parwan prison there which has an estimated 5,000 to 7,000 prisoners, including hardened Taliban and al Qaeda fighters, according to the officials, who spoke on the condition of anonymity.

In 2012, at its peak, Bagram saw more than 100,000 U.S. troops pass through. It was the largest U.S. military installation in Afghanistan.