VOI - Voice of Indonesia | RRI - Radio Republik Indonesia

The navies of South Korea, the U.S. and Japan will hold two days of anti-submarine exercises starting Monday to better counter North Korea's evolving nuclear and missile capabilities, South Korea's defence ministry said.

The drills will be staged in international waters off South Korea's southern island of Jeju, involving a U.S. carrier strike group led by USS Nimitz, which had arrived in the southeastern city of Busan last week. 

The trilateral drills come as North Korea unveiled last week new, smaller nuclear warheads, vowed to produce more weapons-grade nuclear materials to expand its arsenal, and boasted of what it called a nuclear-capable underwater attack drone.

This week's exercises will use a mobile anti-submarine warfare training target to improve the capabilities needed to detect, track and destroy North Korean underwater threats, the ministry said. 

The three countries last held trilateral anti-submarine drills in September - the first time in five years - amid tension over North Korea's unprecedented number of missile tests. (Reuters)