SEOUL - The Republic of Korea's (ROK) President Lee Myung-bak on Thursday urged the Democratic People's Republic of Korea (DPRK) to stop developing nuclear weapons, saying it is essential to ensure peace and stability in northeast Asia.

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Calling the DPRK's nuclear weapons development a "grave threat" to peace in the region and to the non-proliferation regime of the international community, the president said the DPRK should forsake its nuclear program and open up itself for its own good.

"It is imperative that the North dismantle its nuclear arsenal and take the path of openness and development as China and Vietnam have done," Lee said in a speech at an international conference in Seoul. "That is the only alternative that Pyongyang can take for its own sake."

For the two Koreas to reunite, Lee said they should end military confrontation and cooperate to build a peace regime and an economic community.