The U.S. military estimates that it has completed up to a quarter of its pullout from Afghanistan.
"U.S. Central Command (CENTCOM) estimates that we have completed between 16-25% of the entire retrograde process," the command, which oversees operations in Afghanistan, said Tuesday.
CENTCOM also said it had removed the equivalent of approximately 160 C-17 planeloads of material from Afghanistan and had turned over more than 10,000 pieces of equipment to the Defense Logistics Agency for disposition.
U.S. President Joe Biden announced last month that American troops would leave Afghanistan by September 11, after nearly 20 years of military involvement in the war-torn country.
As of Biden's announcement, at least 2,500 U.S. troops made up part of NATO's Afghanistan mission, which includes less than 10,000 troops.
The withdrawal of the U.S.-led NATO force has sparked fears that Afghanistan's civil war could intensify and spiral out of control.
Afghan civilians have been killed in a string of attacks since May 1, when the United States formally began its withdrawal, and the Taliban has made territorial gains across the country, including in Baghlan province in the north, Helmand province in the south, Farah province in the west and Laghman in the east.
It is still unclear whether the Taliban will keep its commitment made in February 2020 to remove ties with al-Qaida. The terror group was responsible for the September 11, 2001, attacks, which killed some 3,000 people on American soil.
U.S. Senate Minority Leader Mitch McConnell urged the president Tuesday to "reconsider" the decision to withdraw, as his diplomatic and military teams "confront him with the risks and consequences."
"When we're gone, there is every reason to believe al-Qaida will regroup in its historic safe haven. Giving up the high ground while the enemy is still on the battlefield isn't a strategic move," said McConnell.
Pentagon Press Secretary John Kirby told reporters on Tuesday the “enemy at play” in Afghanistan is terror groups with dwindling power since the U.S. entered Afghanistan.
“The terrorist threat emanating from Afghanistan has been diminished—not extinguished by any means—but diminished,” he said.
U.S. forces killed Osama bin Laden, the leader of al-Qaida who orchestrated the 2001 attacks, during a raid on his compound in Abbottabad, Pakistan, in May 2011.
U.S. defense officials have argued that planning for how the U.S. will respond to threats from Afghanistan once the pullout is complete is ongoing, hinting in recent weeks that there has been some progress on securing basing agreements to better position U.S. counterterrorism forces.
But despite some optimism, administration officials have yet to announce any specific measures.
"It's still a work in progress," Milancy Harris, the Pentagon's deputy assistant secretary for Special Operations and Combatting Terrorism, told a webinar Tuesday.
McConnell noted Afghanistan's neighbors Iran, Pakistan, and Russian-influenced Central Asian nations "aren't exactly likely to let us base significant counterterrorism units in their countries."
Harris added that the administration is working every day "to make sure we think through and take a really deliberate planning approach to the withdrawal."
"My emphasis is on scalability and responsiveness," Harris said, calling U.S. counterterrorism efforts in Afghanistan until now an example of how the military can work effectively to counter terror groups.
VOA's Jeff Seldin contributed to this report.