Moscow: The head of the UN nuclear watchdog urged Iran Monday to grant IAEA inspectors immediate access to the Parchin facility, the agency reported on its website.
"We consider it essential for Iran to engage with us without further delay on the substance of our concerns," IAEA Director General Yukiya Amano said at the agency`s board meeting.
The IAEA suspects Iran of having conducted nuclear activities at the Parchin military base, 30 km from the capital Tehran.
Tehran has dismissed the allegations as "baseless".
Amano also accused Tehran of failing to provide the necessary cooperation that would let IAEA inspectors "conclude that all nuclear material in Iran is in peaceful activities".
The US, Israel and a number of Western European countries suspect Iran of running a nuclear weapons programme under the guise of a civil nuclear project. Iran denies this and maintains its nuclear ambitions are purely peaceful.