Japan, South Korea and the U.S. have conducted the first joint anti-submarine warfare (ASW) drills involving the three countries amid North Korea¡¯s growing submarine-launched ballistic missile threat.

The three-day drill, which kicked off Monday, was being held in the waters between Japan and South Korea near the island of Jeju and was aimed at developing an ¡°effective response¡± by the three nations to the North¡¯s submarine activities, especially its improving SLBM capabilities, the South¡¯s Defense Ministry said Monday.

The Maritime Self-Defense Force said in a statement the same day that the drill to ¡°bolster tactical cooperation¡± involved the helicopter-carrying Sawagiri destroyer. South Korea sent its own destroyer and helicopter while the U.S. dispatched an Aegis-equipped destroyer and a P-3C Orion patrol plane.