"The US and its followers' despicable act of taking issue with the DPRK's measures for bolstering nuclear force will only result in increasing our hostility to them and furthering the efforts to diversify and modernize our own nuclear force," the spokesman was quoted as saying by the report released in English.

The DPRK refers to the abbreviation of North Korea's full name -- the Democratic People's Republic of Korea.

North Korea fired the ground-to-ground Pukguksong-2 missile, an upgraded version of a submarine-launched ballistic missile, saying that its leader approved its deployment for combat use.

The launch came just a week after the North test-fired a new intermediate-range ballistic missile, called the Hwasong-12.

The UNSC on Monday strongly condemned the North's missile test and warned of additional sanctions against the North.

The spokesman at the foreign ministry said that the US finds faults with Pyongyang's "normal" process to bolster its military capabilities for self-defense.

North Korea has long claimed that its development of nuclear weapons is a deterrent against what it calls Washington's hostile policy toward it. (Yonhap)