U.S., South Korea and Japan Begin Trilateral Air and Naval Exercise Off Jeju

The United States, South Korea and Japan opened a joint air and naval exercise Monday off South Korea’s southern Jeju Island as the three partners sought to bolster combined defenses against growing North Korean nuclear and missile threats.

Called Freedom Edge, the drill is designed to strengthen combined operational capabilities in the sea, air and cyberspace, South Korea’s Defense Ministry said. The U.S. Indo-Pacific Command said the exercise will include U.S. Marine and Air Force aerial assets and will feature enhanced ballistic-missile and air-defense drills, medical evacuations and maritime operations training, calling it "the most advanced demonstration of trilateral defense cooperation to date."

The exercise, which runs through Friday, coincides with heightened tensions on the Korean Peninsula. Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, denounced the drills in state media, calling them a "reckless show of strength" and saying they reflect a confrontational stance toward the North. She also criticized Washington and Seoul over a reported concurrent tabletop exercise called Iron Mace, which aims to explore ways to integrate U.S. nuclear capabilities with South Korean conventional forces to bolster deterrence. U.S. and South Korean militaries did not confirm details of Iron Mace.

Freedom Edge will include ballistic missile defense scenarios and air defense coordination among the three countries, military officials said. The drills also incorporate medical evacuation exercises and combined maritime operations intended to improve interoperability among forces that have conducted more frequent joint activities in recent years.

Seoul and Washington have emphasized the exercises are defensive in nature and necessary to deter and respond to North Korea’s continued development of nuclear weapons and long-range missiles. North Korea has repeatedly condemned joint drills by its neighbors and their U.S. ally, and has in the past staged military demonstrations and weapons tests in response to such exercises.

Analysts and officials note the trilateral drills come amid a broader geopolitical realignment in East Asia. North Korea has resisted calls from Seoul and Washington to resume negotiations aimed at rolling back its weapons programs. In recent months Pyongyang has expanded ties with countries confronting the United States, including sending troops and large shipments of weapons to Russia following its invasion of Ukraine, and raising its diplomatic profile through visits to China and public appearances alongside Chinese and Russian leaders.

The three-way exercises reflect a continuing effort by the United States, South Korea and Japan to deepen practical military cooperation despite historical and political differences among the partners. Trilateral drills have increased in scope in recent years, focusing on interoperability in missile defense, maritime security and crisis response.

Military officials said there was no immediate indication of North Korean military activity in direct response to Monday’s drills. The exercises are scheduled to proceed through Friday unless circumstances prompt an adjustment, the U.S. Indo-Pacific Command said.

The South Korean Defense Ministry and U.S. military spokespeople reiterated that the drills are intended to enhance preparedness and deterrence while minimizing the risk of unintended escalation. North Korea’s state denunciations underscore the persistent security challenges on the peninsula and the difficulties of pursuing diplomatic engagement amid ongoing weapons development and shifting international alignments.