Iran's parliament has approved plans to resume uranium enrichment and end UN snap inspections of its nuclear facilities if it is referred to the UN Security Council for possible sanctions.
The UN nuclear watchdog is due to decide next week whether or not to refer Tehran over its secretive nuclear programme.
The US says Iran is developing nuclear weapons and aims to prevent it enriching uranium, a key stage in producing weapons-grade fuel.
One of the IAEA's demands is to return to the Lavizan-Shian area in Tehran, site of a physics research centre that was dismantled before IAEA inspectors paid an initial visit in June 2004.
Iranian foreign ministry spokesman, Hamid Reza Asefi, has said said the IAEA will not be given access to the site unless it provides 'concrete proof' to justify an inspection.
Under the Non-Proliferation Treaty, Iran is not obliged to provide access to such sites but has allowed some access as a 'confidence-building' measure.
