PYONGYANG, March 2 (Xinhua) -- The military of the Democratic People's Republic of Korea (DPRK) on Thursday threatened to take "the toughest counteractions" against the ongoing South Korea-U.S. joint war games.

"Should the U.S. imperialists and the South Korean puppet forces fire even a single shell into the waters where the sovereignty of our Republic is exercised, the KPA (Korean People's Army) will immediately launch its merciless military counteractions," said a statement given by an unnamed spokesman for the KPA General Staff.

The military will foil the nuclear war racket of the "aggressors" with its treasured nuclear sword, the spokesman added.

South Korea and the United States on Wednesday kicked off their joint springtime war games codenamed "Foal Eagle," which is scheduled to last till the end of April. The USS Carl Vinson aircraft carrier and other U.S. strategic assets will be sent to the Korean Peninsula for the drill, according to local reports.

Also, the military exercise will include a 4D operation plan and will be put under simulated conditions of THAAD (Terminal High Altitude Area Defense) deployment.

Meanwhile on the first day of the exercise, top-level defense and security officials of South Korea and the United States had phone talks to reaffirm the THAAD deployment in South Korea by the end of this year.

Seoul and Washington agreed in July last year to install one THAAD battery by the end of this year. The site was altered in September to a golf course in the Seongju county, North Gyeongsang province.

China and Russia have strongly opposed the THAAD deployment in South Korea as it breaks regional balance and damages security interests of the two countries.

Each spring, South Korea and the Untied States carry out annual joint military drills "Key Resolve" and "Foal Eagle," which they say are of "defensive nature" and aim to cope with threats from the DPRK. Pyongyang has consistently condemned the war games and regarded the drills as "rehearsals for northward invasion."