North Korea on Thursday reiterated its pledge to bolster its nuclear deterrence both in quality and quantity against what it called US hostile acts, the country's state-run media said.

North Korea defended its latest test of intermediate range missiles, saying that it is natural for the country to take steps to boost nuclear deterrence to counter Washington's constant threats, according to the Korean Central News Agency (KCNA).

North Korea “will continue taking a series of steps for bolstering up the nuclear deterrent for self-defense both in quality and quantity to cope with the ever-escalating US hostile acts against the former,” a spokesman at the Foreign Ministry was quoted as saying by the KCNA.

Pyongyang claims that the US constantly poses a nuclear threat to the North, saying that Washington brought strategic assets including nuclear-powered submarine Mississippi and B-52H strategic bombers to the Korean Peninsula.

On June 22, North Korea fired two ballistic missiles from its eastern shore, South Korea and the United States said.

North Korea’s southern rival, South Korea, immediately condemned the action from its isolated and controversial neighbor.

“According to the U.N. Security Council resolution, any launches that involve ballistic missile technology are a violation of the treaty and we think this is clearly a provocation towards us,” said spokesman Jeong Joon Hee of South Korea’s Unification Ministry.

The test was met with the expected denunciation from North Korea’s main opponents - the South, the United States, NATO, and Japan.

Japanese Prime Minister Shinzo Abe said that this country could “never forgive” the test. Japanese Defense Minister Gen Nakatani said “the threat to Japan is intensifying.”

Cmdr. Dave Benham, spokesman for the United States Pacific Command, said both missiles are believed to be Musudan intermediate-range missiles, and they were fired from the North Korean port city of Wonsan.

The Musudan has a strike range of 1,553 to 2,485 miles.

A South Korean official told CNN that the first missile only flew 93 miles, and is being considered a failed launch. The second missile, however, flew 249 miles and is still being investigated.

“The North Korean regime must realize that complete isolation and self-destruction await at the end of reckless provocation,” South Korean President Park Geun-hye said.

She was seconded by NATO Head Jens Stoltenberg who condemned the “provocative actions.”