South Korea’s president has called for deeper security cooperation with the U.S. and Japan to address North Korea's nuclear threat, saying his upcoming summit with the U.S. and Japanese leaders at Camp David will “set a new milestone in trilateral cooperation.”

South Korea’s president has called for deeper security cooperation with the U.S. and Japan to address North Korea’s nuclear threat, saying his upcoming summit with the U.S. and Japanese leaders at Camp David will “set a new milestone in trilateral cooperation.”