The nuclear-powered aircraft carrier USS Ronald Reagan left Yokosuka naval base on Friday for a surveillance mission amid growing tensions over North Korea.

The U.S. flattop, which departed the base in Kanagawa Prefecture shortly after noon, is expected to head for waters around the Korean Peninsula for patrolling activities as part of efforts to deter North Korea from conducting further ballistic missile launches and nuclear testing, informed sources said. It may call at a port in South Korea, the sources added.

Since North Korea's sixth nuclear test on Sunday, the U.S. and South Korean governments have discussed plans for regular dispatches of U.S. aircraft carriers and strategic bombers to areas around the peninsula.

The Ronald Reagan, which belongs to the U.S. Navy's 7th Fleet and carries more than 60 aircraft, constitutes Carrier Strike Group 5 with Aegis ships and submarines equipped with Tomahawk cruise missiles, playing a key role in U.S. military deterrence in the western Pacific.