N. Korea maintains defiant tone

North Korea said Saturday that its nuclear weapons were not a bargaining chip to trade for economic concessions, warning that it would never negotiate with the United States as long as Washington maintained its hostile policy toward the North. The statement was the latest in a series in which North Korea has appeared to harden its position on its nuclear weapons program. Since the U.N. Security Council imposed more sanctions to punish North Korea for its launching of a long-range rocket in December and its third nuclear test last month, the country has said it will no longer attend talks on dismantling its nuclear program.