Pyongyang, North Korea - North Korea staged a "tactical nuclear strike drill" on Wednesday, according to state news agency KCNA on Thursday.

The agency said that drill simulated "scorched earth strikes" at major command centers and operational airfields in South Korea, in response to ongoing military exercises by the US and South Korean armed forces.

North Korea was referring to the launch of two ballistic missiles which, according to the South Korean military, flew about 225 miles in the direction of the East Sea, also known as the Sea of Japan, before falling into the water on Wednesday.

The missile unit of the Korean People's Army (KPA) "correctly carried out its nuclear strike mission through air bursts at a preset altitude of 400 meters [1,300 feet] above the target island," KCNA said, citing the general staff in Pyongyang.

"The drill is aimed to send a clear message to the enemies," the report said.

KPA would "never overlook the rash acts" of US forces and the "military gangsters" of South Korea, it said.

On Wednesday, the US and South Korea undertook an air force exercise over the Yellow Sea between the Korean Peninsula and China.

The exercise took place in connection with the 11-day joint military exercise "Freedom Shield," which is to be completed on Thursday.

North Korea considers the annual US-South Korean joint military exercises an aggressive provocation.

UN resolutions prohibit North Korea from testing ballistic missiles of any range, some of which are capable of carrying a nuclear warhead.