Instead, it repeated a long-standing offer to let international inspectors make unannounced checks as long as the UN Security Council - invoked by the West several months ago to put pressure on Iran - dropped the case.

Head of the International Atomic Energy Agency (IAEA) Mohamed ElBaradei delivered a report on April 27 saying UN checks in Iran had been hampered and Tehran had rebuffed requests to stop making nuclear fuel.

Deputy head of Iran's Atomic Energy Organisation Mohammad Saeedi said that Iran wanted the UN Security Council, which has the power to impose sanctions, to pass the case back down to the IAEA.

The Additional Protocol to the nuclear Non-Proliferation Treaty allows short-notice inspections of nuclear facilities.

Iran insists it is merely using its sovereign right to enrich uranium at a low level to fuel power stations - and not aiming for the highly enriched form that could power a warhead.

Reuters