The UN nuclear watchdog and Iran have agreed to hold talks in Vienna on Friday, IAEA chief Yukiya Amano said Monday, calling on Tehran to sign a deal clarifying issues over its atomic drive.

"A meeting between Iran and the agency has been scheduled for 8 June in Vienna," Amano told the International Atomic Energy Agency's 35-member board of governors at the start of a week-long meeting.

"I invite Iran to sign and implement the Structured Approach document as soon as possible and to provide early access to the Parchin site," Amano said, referring to a military base near Tehran.

The IAEA is seeking an accord with Tehran to guarantee swift and unconditional access to sites, people and documents related to the Islamic republic's nuclear programme.

After a visit to Tehran on May 21, where he met Iran's chief nuclear negotiator Saeed Jalili, Amano said an accord could be signed "quite soon," but there is still no sign of any agreement.

Part of the agreement would involve the Parchin base, where the IAEA believes suspicious explosives testing was carried out.

The agency has been seeking access to the site for months, but has so far been denied by Iran, which says Parchin is of no relevance to its nuclear programme and it is not obliged to allow inspections.

In its latest report last month, the IAEA said new satellite imagery of Parchin indicated "extensive activities" at the base, including the razing of two buildings and what experts have described as a clean-up at the base.

This "could hamper the agency's ability to undertake effective verification" of the site, the IAEA report warned.