UN powers warn on N Korea and Iran
The UN Security Council's five permanent members have said North Korea and Iran pose "serious challenges" to the world's most important pact on preventing the spread of nuclear arms.
A joint statement by Britain, China, France, Russia and the United States also calls for a nuclear weapons-free zone in the Middle East, where Iran enjoys close ties with Russia.
Friday's statement preceded two weeks of talks in Geneva over the 1970 Nuclear Non-Proliferation Treaty, which has been signed by 190 nations. North Korea and Iran are not members.
Sen Pang, director-general of China's Arms Control and Disarmament Department, whose nation has close ties to North Korea, cautioned against a "vicious cycle" of confrontation with North Korea which could lead to war.