South Korea and the United States on Monday began two days of joint naval exercises off the east coast involving the nuclear-powered U.S. aircraft carrier.

The 97,000-ton USS Nimitz (CVN 68) left the southeastern port of Busan earlier in the day for the exercises with South Korea's Navy in the East Sea near Pohang, a senior military official said.

The Nimitz Strike Group consists of the aircraft carrier USS Nimitz (CVN 68) and guided-missile destroyers and cruisers.

South Korea mobilized the Aegis-equipped destroyer King Sejong and the DDH-II class destroyer Chungmugong Yi Sunshin for the exercises. Aegis destroyers of the two countries will carry out missile detection, anti-submarine and anti-aircraft maneuvers, military officials said.

Details of naval powers mobilized in the drill were not disclosed. 

Although Seoul and Washington have said the maneuvers are part of annual training and defensive in nature, North Korea on Saturday denounced the arrival of the nuclear-powered aircraft carrier.

Pyongyang's Secretariat of the Committee for the Peaceful Reunification of Korea described the arrival as "an open threat and blackmail against the DPRK (North Korea), and a grave military provocation to unleash a nuclear war against it at any cost on the Korean Peninsula."

North Korea has long bristled at military exercises between the U.S. and the South, denouncing them as a rehearsal for an invasion of the communist nation. (Yonhap News)