The International Atomic Energy Agency (IAEA) has told Iran that it needs to increase its cooperation with the nuclear watchdog in its probe assessing allegations that Tehran has worked to create nuclear weapons.
In a report published on May 29, the IAEA said Iran had provided some information to the agency about one of two issues but needed to answer questions and provide access to the Parchin military base.
Western officials have charged that Iran carried out explosives tests at Parchin that are relevant to the development of nuclear weapons.
The IAEA report comes as six world powers are working to finalize an accord with Iran that would curb its disputed nuclear program in exchange for relief from economic sanctions.
The two sides have set a June 30 deadline for signing an agreement.
Iran has insisted that its nuclear program is only for peaceful purposes.
But Washington says sanctions relief can only come if Tehran fully resolves all IAEA questions in its probe.