Navy ships South Korea, the United States and Japan jointly conduct drills in waters south of the Korean Peninsula, Jan. 17. Yonhap

North Korea has conducted a test of an underwater nuclear weapons system to this week's joint naval drills by South Korea, the United States and Japan, the state-run KCNA said Friday.

The test of the "Haeil-5-23" system, a name North Korea has given to its nuclear-capable underwater attack drones, was carried out by its defense ministry's think tank in waters off its east coast, the report said, without specifying a date.

The ministry's unnamed spokesman accused the United States, South Korea and Japan of "getting frantic" with military exercises, warning of "catastrophic consequences."

The three countries' three-day regular exercise finished Wednesday, involving the U.S. aircraft carrier Carl Vinson, and was part of efforts to improve their responses to Pyongyang's evolving nuclear and missile threats.

"Our army's underwater nuke-based countering posture is being further rounded off and its various maritime and underwater responsive actions will continue to deter the hostile military maneuvers of the navies of the U.S. and its allies," the North Korean ministry spokesman said in a statement, according to the KCNA.

North Korean state television has aired previous nuclear tests, which were monitored by the U.S. and South Korean authorities, but the reported underwater weapon has not been independently verified.

Dubbed "Haeil," which means tsunami, the new drone system was first reportedly tested in March 2023, and state media said it was intended to make sneak attacks in enemy waters and destroy naval strike groups and major operational ports by creating a large radioactive wave through an underwater explosion.

The latest reported test came days after North Korea fired a new intermediate-range, solid-fuel hypersonic missile, which Washington, Seoul and Tokyo condemned as a serious violation of U.N. Security Council resolutions.

The three allies' nuclear envoys gathered in Seoul, Thursday, also condemning Pyongyang's arms trade with Russia and increasingly hostile rhetoric, at the same time as the North Korean foreign minister's visit to Moscow where she met with President Vladimir Putin. (Reuters)

（作者：汽车音响）