Tensions between Iran and the International Atomic Energy Agency (IAEA) have repeatedly flared in recent years and were further inflamed after a 12-day war in June that saw Israeli and US strikes on key Iranian nuclear facilities.

Since the war, agency inspectors have not been granted access to sites such as Fordo and Natanz, which were hit in the strikes, but they have been able to visit other sites.

"We have performed a number of inspections, but we have not been able to go to the attack sites. I hope we will be able. Indeed, we have to go because this is part of Iran's commitments," IAEA head Rafael Grossi told reporters after opening the regular board meeting of the Vienna-based agency.

"I hope we'll be able to move in a constructive manner."

Britain, France, Germany and the US have submitted a draft resolution to the board, seen by AFP on Wednesday, urging Iran to "cooperate fully" with the IAEA.

The draft, which is expected to be voted on by the IAEA board during its meeting this week, stresses that it is "imperative" for Iran to comply with its obligations under the nuclear non-proliferation treaty.

It also urges Iran to provide "access that the agency requests".

- 'No enrichment' -

Iranian officials warned against adopting an anti-Iran resolution, deputy foreign minister Kazem Gharibabadi saying on Sunday it would force his country to "conduct a fundamental review" of its relations with the agency.

Grossi said on Wednesday it would not be "logical" for a resolution to prompt less cooperation with his agency.

Last week the IAEA called on Iran to allow it to verify its enriched uranium inventories, especially its sensitive stockpile of highly enriched uranium that was "long overdue", according to a confidential report seen by AFP.

"This is the consensus -- and also being confirmed by the Iranian government -- that the stockpile of enriched uranium is still there, so we need to check on that," Grossi said on Wednesday.

In the aftermath of the June war, Tehran suspended its cooperation with the IAEA and restricted the watchdog's inspectors from accessing the bombed sites, accusing it of bias and failing to condemn the attacks.

Iranian Foreign Minister Abbas Araghchi said Sunday that "no enrichment" was taking place at present because the sites were damaged in the Israel war and that the country had no undeclared uranium enrichment sites.

The assertion came after US media reported that Iran had accelerated construction at a secret underground nuclear site called "Pickaxe Mountain", or Kuh-e Kolang, near its Natanz facility.