South Korea, the United States and Japan conducted the first round of regular joint naval exercises in international waters south of Jeju Island for three days ending on Wednesday.

Seoul's Joint Chiefs of Staff(JCS) said the drills involved nine warships, including the South Korean Navy's Aegis combat system-equipped destroyers, the U.S. nuclear-powered aircraft carrier USS Carl Vinson, the Japan Maritime Self-Defense Force's Kongo-class destroyers.

The USS Carl Vinson's return to the Korean Peninsula was the first visit in three months following a visit last November.

The regular drills, aimed at responding to North Korea's nuclear and missile threats, were agreed upon during a trilateral defense ministers' meeting last June. This week's exercises were carried out following the North's launch of a hypersonic missile.

On the first day of the exercises, JCS Chairman Adm. Kim Myung-soo pledged to further reinforce the combined posture of the three countries in accordance with their multiyear exercise plan.