Nearly 2,400 U.S. troops have been killed in America's longest-running war, which began in 2001. Last year was one of the deadliest on record with 23 deaths of U.S. service members, the AP reported.
The Taliban have been resurgent since NATO ended its military mission there in 2014, and the group has been conducting almost daily attacks on Afghan and U.S. soldiers, killing many Afghan civilians in the process. More than half of Afghanistan's population now live in districts controlled or contested by the Taliban.
