Rumyantsev, head of Russia's Federal Atomic Energy Agency, told reporters the conference of 136 countries had sought "to organize international support for national problems of detection, security, safety and disposition of nuclear and other radioactive materials which represent a potential threat to the international community."

In May, Abraham said the United States was giving 450 million dollarsmillion euros) to the initiative, which tries to prevent nuclear materials stored around the world from falling into the hands of terrorists who could use them to make a "dirty" bomb or even a full-fledged atomic device.

The US plan includes working with Russia to repatriate all Russian-origin fresh HEU (highly enriched uranium) nuclear fuel by the end of 2005.

Abraham said Sunday that the United States was not asking other nations to do things it would not do itself as it was also repatriating nuclear fuel and recycling reactors when possible to use low enriched uranium instead of highly enriched uranium (HEU).

"We recognize there is a world in which terrorists are attempting to gain access to either weapons or materials and we intend to stop them. This initiative will make a major contribution to the effort to stop terrorists from acquiring such materials or weapons," Abraham said.

Rumyantsev said that "out of 17 countries that possess highly enriched uranium at research reactors, 13" had agreed to use enriched uranium "at no more than 20 percent," well below bomb-grade levels.

He said the four which had not agreed to this had research reactors which need to use highly enriched uranium of up to 95 percent due to their construction and the experiments they are doing.

The US-Russian initiative is being carried out in coordination with the UN nuclear watchdog, the Vienna-based International Atomic Energy Agency (IAEA).

The IAEA earlier this year oversaw the removal of HEU from a reactor in Libya and its shipment to Russia, which is to return it as low enriched uranium, which cannot be used in a bomb.

The IAEA begins Monday a week-long general conference in Vienna at which it will review its programs and overall aims.

It comes after an IAEA board of governors meeting last week which set a deadline on Iran, which the United States suspects of secretly developing nuclear weapons, to suspend all uranium enrichment activities.

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