SEOUL, May 7 (UPI) -- North Korea is not bound by the global treaty aimed at preventing the spread of nuclear weapons, its U.N. envoy said Thursday, calling efforts to force Pyongyang to comply with the pact a "wanton violation" of international law. Kim Song, North Korea's permanent representative to the United Nations, made the remarks in a statement carried by the state-run Korea Central News Agency during an ongoing review conference of the Nuclear Non-Proliferation Treaty at U.N.