At least 44 Afghan troops who were in the U.S. for military training have gone missing in the last two years, Pentagon officials said. About 2,200 Afghans have come to America to work with the military since 2007. A Pentagon official told Reuters that the number, while small, was “out of the ordinary” and “concerning.” It is unclear if the Afghans have remained in the U.S. illegally. Department of Defense spokesman Adam Stump said all Afghans participating in U.S. training programs on American soil have been vetted to make sure they aren’t associated with extremist groups. “The Defense Department is assessing ways to strengthen eligibility criteria for training in ways that will reduce the likelihood of an individual Afghan willingly absconding from training in the U.S. and going AWOL [absent without leave],” Stump said.