A new report from International Atomic Energy Agency chief Mohamed ElBaradei says Iran is still denying access to sensitive "military-owned workshops and research and development locations".

The IAEA wants to return to the Lavizan-Shian area in Tehran, site of a physics research center that was dismantled and the ground razed before IAEA inspectors paid an initial visit in June 2004.

"We only work within the framework of the safeguards, and if they come up with concrete proof within the framework of the safeguards and NPT we will consider it," foreign ministry spokesman Hamid Reza Asefi told reporters, referring to the nuclear Non-Proliferation Treaty.

"They cannot just say we want to talk to this or that person and keep on dragging out the dossier. They should tell us their aims, and these aims should be towards closing the case," Asefi said.

"We have cooperated with the IAEA and will continue doing so. But we will only work within the framework of the NPT and the safeguards, and will not accept anything further."