NKorea threatens to bolster its nuclear arsenal

North Korea is threatening to bolster its nuclear arsenal at any cost amid worries that the country may conduct a third atomic test soon.

The Committee for the Peaceful Reunification of Korea says a U.S. call for Pyongyang to give up its nuclear and space development programs is a "grave provocation."

An unidentified committee spokesman says the North will further strengthen its "nuclear deterrent" to protect its sovereignty "regardless of whatever the price it would pay."

His remarks were carried Thursday by the official Korean Central News Agency.

The U.N. Security Council imposed fresh sanctions on North Korea as a response to its failed rocket launch last month, and there is concern that Pyongyang is preparing for its third nuclear test.