Seoul, South Korea (Reuters): North Korea warned the United States on Tuesday of "merciless" attacks if an aircraft carrier strike group led by the USS Carl Vinson, which is joining South Korean forces for exercises, infringes on its sovereignty or dignity.
North Korea , which has alarmed its neighbors with two nuclear tests and a string of missile launches since last year, said the arrival of the U.S. strike group was part of a "reckless scheme" to attack it.
The North's state news agency KCNA said, "If they infringe on the DPRK's sovereignty and dignity even a bit, its army will launch merciless ultra-precision strikes from ground, air, sea and underwater."
KCNA said, "On March 11 alone, many enemy carrier-based aircraft flew along a course near territorial air and waters of the DPRK to stage drills of dropping bombs and making surprise attacks on the ground targets of its army."
A U.S. Navy spokesman said the Carl Vinson was on a regular, scheduled deployment to the region during which it would take part in exercises with the forces of ally South Korea .
U.S. Secretary of State Rex Tillerson is due to make his first visit to South Korea on Friday.
Compounding regional tension, China is vehemently opposed to the deployment in South Korea of an advanced U.S. anti-missile system.
The United States and South Korea say the Terminal High Altitude Area Defense anti-missile system is for defense against North Korea , but China fears its powerful radar can probe deep into its territory and compromise its security.
South Korean and U.S. troops began the large-scale joint drills , which are billed as defensive in nature, on March 1.
The exercise last year involved about 17,000 American troops and more than 300,000 South Koreans. South Korea has said this year's exercise would be of a similar scale.
The United States has also started to deploy "Gray Eagle" attack drones to South Korea , a U.S. military spokesman said on Monday.
The drills sent the North "an explicit radical threat", to which it could not be expected to remain indifferent, the influential Global Times said. North and South Korea were "equally hysterical", it said.
"The U.S. and South Korea often accuse China of being uncooperative, but the reality is they are uncooperative over China's mediation," it said, referring to complaints that China does not do enough to rein in old ally North Korea .