ISLAMABAD, Pakistan — The Pentagon has reduced the number of U.S. troops in Afghanistan to 2,500, according to a statement Friday, completing a previously announced rapid drawdown despite a congressional prohibition of the move and rising levels of violence in the country.

“This drawdown brings U.S. forces in the country to their lowest levels since 2001,” said Acting defense secretary Christopher Miller in the statement. Miller also said “the United States is closer than ever to ending nearly two decades of war and welcoming in an Afghan-owned, Afghan-led peace process to achieve a political settlement and a permanent and comprehensive ceasefire.”

But violence is increasing in many parts of Afghanistan, and peace talks in Qatar have made little progress since they were launched in September.

Both Democratic and Republican lawmakers opposed the drawdown to 2,500 troops in Afghanistan, and forbid the Pentagon from using money in this year’s or last year’s budget to carry out the reduction. Congress included a provision on the matter in the National Defense Authorization Act passed earlier this month.

The provision stated that the Trump administration could only access the funds by either submitting an assessment of what effect the reduction in forces would have on the ongoing counterterrorism mission, or by submitting a waiver with a written explanation that the move is important to U.S. national security interests.

The Pentagon statement Friday did not mention an assessment or waiver that would allow the reduction to be carried out despite the congressional prohibition. But a Pentagon spokesman said President Trump decided to issue a waiver.

“The President has determined that waiving the limitations of this section with respect to a reduction in the total number of U.S. armed forces deployed to Afghanistan is important to the national security interests of the United States,” Army Maj. Rob Lodewick said in a statement Friday.

Trump signed the waiver Thursday night, but congressional leadership is not expected to receive it until next week, according to a Defense official and a congressional aide who both spoke on the condition of anonymity because they were not authorized to discuss procedural specifics with the media.

Opposition to the drawdown centered on concerns over counterterrorism and the U.S.-Taliban deal reached last year. Some lawmakers said it was unclear if 2,500 troops would be enough to carry out effective counterterrorism operations in Afghanistan. Others said the troop cuts could violate the deal with the Taliban, which stated U.S. troop reductions would be conditions-based.

The central condition of the deal was a call for the Taliban to break ties with international terrorist groups including al-Qaeda and the Islamic State. Afghan and United Nations officials have reported that the Taliban maintain ties to al-Qaeda. The special U.S. envoy for Afghanistan, Zalmay Khalilzad, said the Taliban still has “work to do before they satisfy their commitments.”

Al-Qaeda’s Sept. 11, 2001, attacks and the Taliban’s refusal to hand over the group’s leader spurred the launch of the U.S. war in Afghanistan. In the Pentagon statement Friday, Miller said a force of 2,500 U.S. troops is sufficient to prevent similar attacks in the future.

“Commanders have what they need to keep America, our people and our interests safe,” Miller said. The U.S. mission there will continue to “ensure that Afghanistan is never again used to harbor those who seek to bring harm to the United States of America.”

The U.S.-Taliban deal calls for a complete withdrawal of U.S. forces by May, but it is unclear how the incoming Biden administration will handle further troop withdrawals. Biden has said repeatedly he plans to keep a relatively small number of U.S. troops — “several thousand” — in Afghanistan for counterterrorism purposes.