"Iran is likely to be cautious. They want to get through the November 24 board" of governors' meeting of the UN watchdog International Atomic Energy Agency (IAEA), non-proliferation expert Gary Samore told AFP.

In a resolution on September 24, the Vienna-based IAEA threatened to refer Tehran to the UN Security Council over its nuclear programme, which the United States claims is a cover for weapons development, but this is not expected to happen before the November board meeting.

The United States on Monday urged all countries to freeze nuclear cooperation with Iran but Russia, which has a lucrative contract to build the Islamic Republic's first nuclear power plant, was not expected to heed this call.

The IAEA resolution, drafted by EU states Britain, France and Germany, cites Iran for having resumed nuclear fuel cycle work it had voluntarily suspended to show its nuclear intentions were peaceful.

The IAEA also accused Iran of hiding sensitive atomic activities in violation of the nuclear Non-Proliferation Treaty (NPT).

Iran's first reaction was a threat to move ahead on making enriched uranium, which can be fuel for nuclear power reactors or the explosive core of atom bombs. Tehran also warned it could withhold oil from a tight world market.

Diplomats said such measures would have forced the IAEA board to meet earlier than planned, possibly hastening a referral to the UN Security Council, which has the power to impose penalties on Iran.

But Iran held off from a precipitous move, saying it will only begin enrichment if it is actually referred to the world body.