A U.S Army CH-47 Chinook helicopter transports a military vehicle during a U.S.-South Korea joint live-fire military exercise at a training field in Pocheon, south of the demilitarized zone separating the two Koreas, March 25, 2015. The exercise is part of Foal Eagle, an annual military training between U.S. and South Korea that runs from March 2 to April 24. REUTERS/Kim Hong-Ji