The head of the U.N. nuclear watchdog agency has described North Korea as a serious challenge to nuclear non-proliferation efforts. In a speech to the General Assembly, agency chief Mohammed ElBaradei also urged Iran to suspend nuclear enrichment activities.

ElBaradei

Mr. ElBaradei told the 191-member Assembly that the International Atomic Energy Agency has not performed verification activities in North Korea since the end of 2002. As a result, he said the U.N. nuclear agency could not be sure there had not been any diversion of nuclear material.

"The situation in the Democratic People's Republic of korea continues to pose a serious challenge to the nuclear non-proliferation regime," Mr. ElBaradei says.

In separate comments to reporters, Mr. ElBaradei expressed frustration at the failure of the six-party talks aimed at pressing North Korea to dismantle its nuclear weapons program in exchange for economic benefits and security guarantees.

"It is slow, I am frustrated it is not moving as fast as it should," Mr. ElBaradei says. "I am telling the North Koreans again the international community is ready to look into your security concerns, to your economic and humanitarian needs, but the prerequisite is for them to commit themselves to full and verifiable dismantlement of their weapons program."

On Iran, Mr. Baradei reported some progress. But he said movement was slow, and urged the Tehran government to halt its uranium enrichment and reprocessing activities.

"Iran has reversed some of the suspension measures initially undertaken in November, 2003 and the board has called on Iran again to suspend all enrichment-related and reprocessing activities as a confidence-building measure," Mr. ElBaradei says.

In his General Assembly address, Mr. ElBaradei did not mention the controversy over nearly 345-metric tons of explosives said to be missing in Iraq. His report last week that the explosives were unaccounted for at a military base near Baghdad has become an issue in the final days of the U.S. presidential campaign.

The U.N. nuclear agency chief did, however, express hope that his inspectors would be allowed to return to Iraq to settle once and for all the question of Saddam Hussein's possession of weapons of mass destruction.

The U.N. nuclear agency was ordered to stop its inspections in March of last year, after finding no evidence of any revival of Iraq's nuclear weapons program. Referring to that conclusion, Mr. El Baradei told the Assembly that the international community is reassured that the agency's findings have been validated.