UNITED NATIONS, Oct 24 (Reuters) - U.N. Secretary-General Ban Ki-moon urged the world's nuclear powers on Friday to take steps to abolish their atomic arsenals and outlined a set of proposals for eliminating all weapons of mass destruction. "Nuclear weapons produce horrific, indiscriminate effects. Even when not used, they pose great risks," Ban told a conference organized by the East-West Institute."

"Accidents could happen any time. The manufacture of nuclear weapons can harm public health and the environment," he said. "Of course, terrorists could acquire nuclear weapons." The permanent members of the U.N. Security Council -- the United States, Britain, France, Russia and China -- signed the 1968 nuclear Non-Proliferation Treaty, under which they pledged to negotiate steps on scrapping their nuclear weapons.