The US has begun withdrawing some troops from Afghanistan, part of the initial drawdown to 8,600, a spokesman for US Forces in Afghanistan announced on Monday. The move is part of the historic agreement signed between the US and Taliban late last month that sets into motion the potential for a full withdrawal of US troops who have been fighting in the country since 2001. The US has 135 days from the signing of the agreement to reduce troop numbers from the current total of 12,000 to 13,000 currently in the country. “In accordance with the U.S.-Islamic Republic of Afghanistan Joint Declaration and the U.S.-Taliban Agreement, U.S. Forces Afghanistan (USFOR-A) has begun its conditions-based reduction of forces to 8,600 over 135 days. USFOR-A maintains all the military means and authorities to accomplish our objectives—including conducting counterterrorism operations against al-Qaeda and ISIS-K and providing support to the Afghan National Defense and Security Forces. USFOR-A is on track to meet directed force levels while retaining the necessary capabilities,” US Forces Afghanistan spokesman Col. Sonny Leggett said in a statement. If the Taliban meet the conditions of the agreement, the remaining US troops are supposed to depart within 14 months. The Associated Press first reported the drawdown had begun. While US officials have repeatedly stressed that the withdrawal is “conditions based,” the initial drawdown comes as the Taliban has continued to conduct dozens of deadly attacks against America’s Afghan allies. The US military has carried out at least one drone strike against the Taliban in defense of local Afghan troops. The conditions that the Taliban are expected to adhere to as part of the agreement are also unclear as defense officials have said that some of those conditions are not being released to the public. Secretary of Defense Mark Esper told reporters at the Pentagon last week that some of the information is detailed in “two classified implementation arrangement documents” developed by the Department of State in consultation with the Department of Defense. The secrecy surrounding the deal has led some to criticize the agreement for its lack of transparency and the inability to hold the Taliban to account. The initial drawdown is also taking place despite the fact the “intra-Afghan negotiations” mandated by the agreement will not begin on Tuesday, which was the date laid down in agreement, according to a source familiar with the planning. The source added that the parties are trying to find a new date later this month for the negotiations to begin, but things are fluid as it is proving complex getting both sides to the table. Those intra-Afghan negotiations were cited by US negotiators as a major accomplishment of the deal amid violence and tensions between the Taliban and Afghan government. Tomorrow Afghanistan’s President Ashraf Ghani is expected to announce who will be at the negotiating table for the Afghan side and the list will include multiple women, the source said. He will also announce the terms of a Taliban prisoner release. The source did not share the details of the release terms, but said it will be linked to a reduction in violence in Afghanistan. The US-Taliban agreement committed to the release of “up to” 5,000 Taliban prisoners before the dialogue began, but Ghani immediately pushed back and said that commitment was never made. US Secretary of State Mike Pompeo did not offer any specifics on a way forward when he was asked last week how the parties would overcome the challenges of the prisoner release. “All the parties understand that it’s time for prisoner exchanges to take place. A number of the prisoners being held have served their full sentences,” Pompeo said Thursday. “We need to move that process forward.” This story has been updated with additional reporting and background information.