South Korea bashed North Korea on Friday for its renewed pledge to cling to its nuclear weapons program, saying it would deal sternly with the communist nation's provocative act.

The response by Seoul's defense ministry came after Hyon Yong-chol, the chief of Pyongyang's People's Armed Forces, claimed during an international security conference in Moscow on Thursday that its possession of nuclear weapons "is the direct result of the hostile policy by the United States and ... aimed at eliminating its nuclear threat."

In response, Seoul's defense ministry spokesman, Kim Min-seok, issued a brief statement and expressed "a grave regret."

"North Korea cannot be recognized as a nuclear-weapons state and its possession of any nuclear (programs) cannot be accepted. If it continues to issue threats of war and to be provocative, our military will respond strongly and sternly," Kim said.

Pyongyang has long demanded such recognition despite a flat rejection by the international community, while stressing that it has no intention to give up the nuclear programs as it viewed them as a deterrent against what it claims is Washington's hostility toward it.

The communist country conducted underground detonation tests in 2006, 2009 and 2013, and has threatened to carry out "a new form" of test. (Yonhap)