President Joe Biden will end America’s war in Afghanistan with a phased withdrawal of the remaining U.S. troops there that will conclude by Sept. 11 — the 20th anniversary of the conflict, a senior administration official said Tuesday.

The United States maintains some 2,500 troops and another 1,000 special forces in Afghanistan, working to root out terrorists and train Afghan security forces. NATO and partner forces provide another 7,000 troops and had been waiting for a U.S. decision to plan their own withdrawal or extension. Defense Secretary Lloyd Austin and Secretary of State Antony Blinken are set to meet with NATO Secretary General Jens Stoltenberg Wednesday in Brussels to discuss the plans.