The White House Monday nominated Under Secretary of State John Bolton as the American ambassador to the United Nations, a man known as a hardline conservative supported by U.S. Vice President Dick Cheney. As the State Department's top diplomat for weapons non- proliferation, Bolton's background in negotiating Libya's decision to abandon nuclear weapons could be well-placed at a time the U.S. is pushing for greater U.N. involvement in getting another country, Iran, to dismantle its uranium enrichment programmes. Bolton said the United Nations needed effective reform and that he plans to use American leadership to bring change to the world body. "This is a time of opportunity for the U.N. which, likewise, requires American leadership to achieve successful reform," he said. U.S. Secretary of State Condoleezza Rice announced Bolton's nomination, highlighting Bolton's long career in government, but also saying his "most important work is yet to come". Bolton must be approved by the Senat In New York, U.N. Secretary General Kofi Annan, who has also set U.N. reform at the top of his agenda for the coming year, "warmly" congratulated Bolton on the nomination. Last month, Annan suggested that the Nuclear Non-proliferation Treaty (NPT), adopted 35 years ago, was losing credibility and needed reaffirmation by its signers to make it work in a new global security system. --MORE 2326 Local Time 2026 GMT