South Korea, the United States and Japan conducted a joint naval exercise south of the Korean Peninsula in response to North Korea’s launch of a missile carrying a hypersonic warhead, Seoul’s Joint Chiefs of Staff (JCS) said Wednesday.

The trilateral drills took place from Monday to Wednesday off the southeastern coast of Jeju Island and involved nine vessels from the three countries’ navies, including the nuclear-powered aircraft carrier USS Carl Vinson.

The JCS said that the exercise included the South Korean Navy’s Aegis combat system-equipped destroyers and the Japan Maritime Self-Defense Force’s Kongo-class destroyers.

The drills began the day after Pyongyang launched its first missile of the year — a solid-fuel intermediate-range ballistic missile (IRBM) carrying a hypersonic warhead — into the East Sea.

“The exercise is aimed at strengthening the three countries’ deterrence capabilities and response to North Korea’s nuclear and missile threats,” the JCS said in a news release, adding that the drills are also “focused on responding to maritime security threats, including shipments of weapons of mass destruction, and enhancing trilateral cooperation in enforcing the rules-based international order.”

The joint exercise is the first trilateral drill held after the three countries established a real-time data-sharing system to track North Korean missile launches and agreed to set up a long-term joint training program to counter the threat emanating from Pyongyang’s advancing arsenal of illicit weapons.

The JCS noted that JCS Chairman Adm. Kim Myung-soo and Gen. Paul LaCamera, commander of United States Forces Korea, visited the USS Carl Vinson on the first day of the exercise.

In a news release, LaCamera said that sailors from the three countries “conducted critical training to continue to enhance interoperability” among their navies, adding that such trilateral exercises “help to maintain the readiness of our naval forces and sharpen our combined skills.”

According to the JCS, Kim also emphasized the importance of cooperation between the three countries and pledged to bolster the combined security posture through exercises.

BY MICHAEL LEE [lee.junhyuk@joongang.co.kr]