RUSSIA, CHINA SEE NO IMMEDIATE THREAT

But Russia and China, two of the five veto-holding Security Council powers, have balked at a Western thrust to brand Iran a "threat to international peace and security" in the proposed Council resolution.

They argue this could lead to U.S.-led military action against a state not proven to be seeking atomic bombs in secret.

China on Tuesday stuck to its position that the dispute should be resolved through diplomatic means.

"As a signatory to the (nuclear) Non-Proliferation Treaty, Iran has the right to peacefully use nuclear energy," Liu said.

"But it should also fulfil its responsibilities and promises to cooperate with the IAEA and regain the trust of the international community," he said.

Iran hid uranium-enrichment research from U.N. nuclear inspectors for almost 20 years, continues to deflect U.N. probes and has failed in Western eyes to justify why it needs nuclear power when it is the world's No. 4 oil producer.

But IAEA chief Mohamed ElBaradei has said Iran poses no imminent security threat and believes that sanctions or war would only drive Iranian nuclear activity underground.

He has urged the West to seek a face-saving accord with Iran that might allow it to keep limited enrichment under strict IAEA monitoring and address security issues that have stoked U.S.-Iranian hostility for 27 years.

Vienna diplomats said Iran signaled in recent contacts with the IAEA that it could renounce "industrial scale" enrichment and reinstate short-notice IAEA inspections if it could maintain a "research and development" program.

Enriched to a low level, uranium can fuel nuclear power plants, a technological threshold Iran reached with a pilot cascade of 164 centrifuges in April. Highly-enriched uranium (HEU) can cause the chain reaction that detonates atomic bombs.

But nuclear scientists say Iran has yet to prove it can run finely calibrated centrifuges without breakdown for the extended periods needed to enrich uranium in more than minute amounts.

They estimate Iran remains 3-10 years away from the capacity to yield enough HEU for one nuclear weapon.