President Joe Biden plans to withdraw all remaining troops from Afghanistan by Sept. 11, the 20th anniversary of the terrorist attacks on America that destroyed the World Trade Center, damaged the Pentagon and forced the country into the longest war in U.S. history, according to reports citing high-level government officials.

More than 3,000 American soldiers will remain on the ground in the war-torn country beyond the May 1 withdrawal deadline previously announced under former President Donald Trump ― an agreement that was reached in ceasefire negotiations last year with the Taliban.

Biden’s decision for a phased withdrawal was first reported early Tuesday by The Washington Post. The president is expected to make a formal announcement of the plan Wednesday.

It was unclear whether the Taliban militants would continue to honor an agreement not to attack U.S. and NATO troops if their withdrawal from the country was not achieved by the May deadline.

For now, there are between 2,500 and 3,500 U.S. troops in Afghanistan along with an additional 7,000 foreign forces, the majority of them NATO troops, according to the Post.

Just last week, Biden acknowledged the challenge of completing a full withdrawal from the country with only weeks to spare.

“It’s going to be hard to meet the May 1 deadline,” he said. “Just in terms of tactical reasons, it’s hard to get those troops out.” Tellingly, he added, “And if we leave, we’re going to do so in a safe and orderly way.”

Biden’s administration has reviewed several options to get out of Afghanistan, where U.S. peace talks have not lived up to expectations and the Taliban continue to be a thorn in the side of American efforts to stabilize the country.

After two decades, more than 2,000 U.S. servicemembers have been killed along with at least 100,000 Afghan civilians in the war that has also cost trillions of U.S. dollars.

“This is the immediate, practical reality that our policy review discovered,” the person familiar with the deliberations said, according to the Post. “If we break the May 1 deadline negotiated by the previous administration with no clear plan to exit, we will be back at war with the Taliban, and that was not something President Biden believed was in the national interest.

“We’re going to zero troops by September.”

The decision demonstrates the willingness of the Biden administration to shift the nation’s global strategy away from the War on Terror to new priorities, including domestic infrastructure challenges and the increasing threat from China’s military.

“The reality is that the United States has big strategic interests in the world like non-proliferation, like an increasingly aggressive and assertive Russia, like North Korea and Iran, whose nuclear programs pose a threat to the United States,” as well as China, according to the source who spoke exclusively to The Washington Post. “The main threats to the American homeland are actually from other places: from Africa, from parts of the Middle East — Syria and Yemen.”

“Afghanistan just does not rise to the level of those other threats at this point,” the source told the Post. “That does not mean we’re turning away from Afghanistan. We are going to remain committed to the government, remain committed diplomatically. But in terms of where we will be investing force posture, our blood and treasure, we believe that other priorities merit that investment.”

Congress has been cautious about reducing the U.S. military presence in Afghanistan. Last year it expressly forbade the Pentagon from using funds to reduce below 4,000 troops, but the Pentagon went ahead anyway after Trump ordered a reduction to 2,500 after he lost the election. Trump got around the legal prohibition by signing a waiver.

Some officials have warned that a full U.S. departure will lead to the collapse of the country’s fledgling government and likely throw away any gains made over the last two decades in health, education and women’s rights.

“A withdrawal would not only leave America more vulnerable to terrorist threats; it would also have catastrophic effects in Afghanistan and the region that would not be in the interest of any of the key actors, including the Taliban,” a bipartisan experts group known as the Afghan Study Group concluded in a February report. The group, whose co-chair, retired Gen. Joseph Dunford, is a former commander of U.S. forces in Afghanistan and former chairman of the Joint Chiefs, recommended Biden extend the deadline beyond May, preferably with some sort of agreement by the Taliban.

But postponing the U.S. withdrawal carries the risk of the Taliban resuming attacks on U.S. and coalition forces, possibly escalating the war.

If the troops stay, Afghanistan will become Biden’s war. His decisions, now and in coming months, could determine the legacy of a 2001 U.S. invasion that was designed as a response to al-Qaida’s Sept. 11 attacks, for which the extremist group led by Osama bin Laden used Afghanistan as a haven.

Biden said during the 2020 campaign that if elected he might keep a counterterrorism force in Afghanistan but also would “end the war responsibly” to ensure U.S. forces never have to return.

In a February 2020 agreement with the administration of President Trump, the Taliban agreed to halt such attacks and hold peace talks with the Afghan government, in exchange for a U.S. commitment to a complete withdrawal by May 2021.

This is a breaking news development. Please stay with AJC.com for the latest updates. Information provided by The Associated Press was used to supplement this report.