N. Korea threatens military response

North Korea said Wednesday it was nullifying the Korean War armistice and warned of an immediate military strike should South Korea attempt to interdict any of its ships, blasting Seoul`s participation in a U.S.-led security campaign as a "declaration of war."

The statement, issued by the North`s permanent military mission to the joint security area, also said the country can no longer guarantee the safety of South Korean and U.S. military ships and private vessels moving along the western sea border, according to Yonhap News.

"As declared to the world, our revolutionary forces will consider the full participation in the Proliferation Security Initiative by the Lee Myung-bak group of traitors as a declaration of war against us," the North Korean military mission said, referring to the South Korean president, in a statement carried by Pyongyang`s official Korean Central News Agency (KCNA).

South Korea joined the Proliferation Security Initiative (PSI) on Tuesday, reacting sternly to the North`s nuclear test a day earlier. The PSI allows participating countries to interdict and seize ships and planes suspected of carrying weapons of mass destruction. Pyongyang views the exercise as a violation of the Korean War armistice, which bans any attempt of naval blockage in the region.

The North`s military "will be no longer bound to the armistice agreement" that ended the 1950-53 war, and the peninsula will be returned to the state of war if the armistice becomes ineffective, the mission said.

With the armistice now ineffective, the North can no more guarantee the safety of U.S. and South Korean naval vessels and other commercial vessels sailing along the inter-Korean border in the Yellow Sea, the mission said.

"If the armistice agreement is terminated, the Korean Peninsula in terms of law is bound to return to the state of war and our revolutionary forces will get to move on to pertinent military actions," the mission said.

"Any trivial attempts, including the act of interdicting and inspecting our peaceful ships, will be acknowledged as an unacceptable violation of the sovereignty of our republic, and we will respond with an immediate and strong military strike," it said.