USS George Washington
Nuclear-powered super-carrier USS George Washington arrives at a port of South Korean navy in Busan on Oct. 4, 2013. Reuters

North Korea has ordered its army to be prepared to launch an attack and warned the U.S. of “disastrous consequences” over the latter's joint maritime drills commencing on Tuesday with South Korea and Japan in waters off the southern coast of the Korean peninsula.

Pyongyang said it put the Korean People’s Army, or KPA, on high alert after a nuclear-powered U.S. aircraft carrier, the USS George Washington, arrived on Oct. 4 in the South Korean port city of Busan, 450 kilometers (280 miles) south of Seoul, accompanied by missile cruiser, USS Antietam CG-54, and a destroyer, USS Preble DDG 88.

“All services and army corps level of the KPA received an emergency order from its supreme command on October 5 to reexamine the operation plans already ratified by it and keep themselves fully ready to promptly launch operations any time, watching with high vigilance every move of the U.S. and Japanese aggressors and the (South Korean) puppet forces,” a KPA spokesman said in a statement published by KCNA, the North Korean government’s mouthpiece.

The latest belligerent rhetoric from Pyongyang comes after a cooling-off period that followed weeks of increased tensions in the Peninsula, beginning in March, when the reclusive Communist nation rejected the armistice that ended the war between the two Koreas in 1950-53, and threatened nuclear attacks against the U.S. and South Korea.

Pyongyang described the joint drills as a “military offensive” to pressure the government to give up its nuclear program, adding: “If the U.S. administration stands for the denuclearization of the Korean Peninsula and is interested in the peace and security in the region, the U.S., not the DPRK (North Korea), should make a decision to move first.”

Meanwhile, South Korea defended the scheduled three-day joint drills as “defensive,” adding that Pyongyang’s accusations were without grounds.

“The maritime training between South Korea, the U.S. and Japan is a humanitarian training exercise to search and rescue private ships that meet with a disaster,” South Korea’s Defense Ministry spokesman Kim Min-seok said in Seoul, according to Xinhua.

The U.S. regularly conducts joint military exercises with Seoul in the waters off the Korean peninsula and has 28,500 troops stationed in South Korea.