"Although we averted a nuclear nightmare during the Cold War, we now face proliferation of a scope and complexity that demands new strategies and new approaches," said Obama.

"Just one nuclear weapon exploded in a city -- be it New York or Moscow, Tokyo or Beijing, London or Paris -- could kill hundreds of thousands of people," he said. "And it would badly destabilize our security, our economies, and our very way of life."

Russian President Dmitry Medvedev said his country continues to reduce nuclear arms "way ahead of schedule," adding that all of its nuclear weapons are "located on its national territory and under reliable protection."

Medvedev also highlighted the "unprecedented" reductions of strategic nuclear arsenals by Russia and the United States.

Chinese President Hu Jintao (Front) addresses the Summit on Nuclear Non-Proliferation and Nuclear Disarmament at the United Nations headquarters in New York Sept. 24, 2009. The U.N. Security Council on Thursday unanimously adopted a resolution to stop the proliferation of nuclear weapons in a bid to seek a safer world for all, and to create conditions for a world without nuclear weapons. [Ju Peng/Xinhua]

Removing the threat of nuclear war is vital to realizing a safer world for all, Chinese President Hu Jintao said, while acknowledging that nuclear disarmament remains a "long and arduous" task.

He put forward a series of measures, including abandoning the nuclear deterrence policy based on first use and taking credible steps to reduce the threat of nuclear weapons.

President Oscar Arias of Costa Rica said the UN had been founded on the promise that all people would able to sleep peacefully, but that promise had not been kept.

"While we sleep, death is awake. Death keeps watch from the warehouses that store more than 23,000 nuclear warheads, like 23,000 eyes open and waiting for a moment of carelessness," he stated, adding that it did not seem plausible to discuss disarmament as long as existing agreements were not being honored.

While affirming the right of nations to peaceful uses of nuclear energy, the resolution called for stronger safeguards to reduce the likelihood that peaceful nuclear programs can be diverted to a weapons program, as well as stricter national export controls on sensitive nuclear materials.

Outgoing Director-General Mohamed ElBaradei of the International Atomic Energy Agency (IAEA) spoke of the need to strengthen and empower the International Atomic Energy Agency (IAEA) if it is to play a role in nuclear disarmament.

"Our verification mandate is centered on nuclear material. If the Agency is to be expected to pursue possible weaponization activities, it must be empowered with the corresponding legal authority," he said.

The Council summit comes ahead of the nuclear security summit to be convened by Obama next April and the NPT Review Conference set for next May. It also coincided with a two-day conference that began at the UN Headquarters on Thursday to try to promote the CTBT and its entry into force.

(Xinhua News Agency September 25, 2009)