South Korea and the United States will launch their annual large-scale military exercise this month to bolster readiness against North Korean threats, the allies said Thursday, in a move likely to irritate Pyongyang amid a prolonged stalemate in diplomacy.

South Korea and the United States will conduct major joint military drills starting on August 18, their military officials said on Thursday, announcing an annual defensive exercise that has been a source of tension with North Korea.

U.S. Army soldiers participate in a joint river-crossing exercise between South Korea and the United States as a part of the Freedom Shield military exercise in Yeoncheon, South Korea, Thursday, March 20,