UN nuclear inspectors say Iran is pressing ahead on a larger scale than ever with the uranium enrichment activities that Western powers suspect are aimed at developing a nuclear bomb, the New York Times reported on Tuesday.
The newspaper said the International Atomic Energy Agency (IAEA) made a short-notice inspection on Sunday of Iran's main nuclear facility in Natanz and found that all of its 1,300 centrifuges were up and running smoothly, producing nuclear fuel.
The centrifuges "were producing fuel suitable for use in nuclear reactors," the US newspaper said, citing diplomats and nuclear experts in Vienna where the agency is based.
It said the plant had overcome earlier technical difficulties in making them spin to produce the material.
Iran has defied months of international pressure and two sets of UN sanctions over its nuclear program, which it insists aims to produce energy for peaceful civilian use.
The material currently being produced by the centrifuges would need to undergo further enrichment before it could be made into bomb-grade fuel.
Reactor-grade uranium is enriched to levels of around five per cent, while weapons-grade uranium must be enriched to 90 per cent or higher.
The paper cited Nicholas Burns, the US undersecretary of state for policy, as saying that if Iran did not agree to suspend the activities by the time of next month's Group of Eight industrial nations' meeting, the United States would press for a third round of sanctions.
The findings, reported by top IAEA officials according to the newspaper, come ahead of a report by the agency to the UN Security Council due early next week.