Yukiya Amano
Yukiya AmanoAFP/Alexander Klein

The head of the UN atomic agency hit out Monday at Iran's refusal to grant access to sites and scientists involved in suspected nuclear weapons research, AFP reported.

International Atomic Energy Agency chief Yukiya Amano called on Iran to open up “without further delay” the Parchin military site, where "powerful tools" could detect traces of covert activities despite Tehran's suspected clean-up work.

Speaking at the start of an IAEA board of governors meeting, where Western nations want Tehran censured, Amano said that in a string of meetings and visits to Iran this year, the two sides had been “going round in circles.”

“This is frustrating because, without Iran's full engagement, we will not be able to start the process to resolve all outstanding issues, including those involving possible military dimensions to its nuclear program,” he said, according to AFP.

The IAEA's latest report on Iran last month said it had doubled enrichment capacity at its Fordo facility, a site dug into a mountain near the holy city of Qom and seen therefore as difficult to destroy.

The centrifuges currently in operation at Fordo are used to enrich uranium to a purity of 20 percent, a short step from producing the 90-percent material needed for a bomb.

At Parchin, one of the sites mentioned in the November IAEA report, Amano said on Monday that activities seen there by satellite “will have an adverse impact on our ability to undertake effective verification there.”

“We have powerful tools to find and trace indicators of the activities. Nevertheless we can know for sure only when we visit the site and take samples,” he was quoted by AFP as having told a news conference.

Western countries hope to use this week's IAEA meeting to turn up the pressure further still on Iran by getting the agency's 35-nation board of governors to approve a resolution sharply criticizing the Islamic republic.

One Western envoy told AFP that he was "reasonably optimistic" that even Russia and China, seen as softer on Iran, would agree to some sort of resolution -- the 12th in nine years.

On Friday, it was reported that several European Union nations are exploring a new raft of sanctions against Iran as exasperation mounts over blocked talks on the country's contested nuclear program.

"We might have to decide soon a new round of sanctions in the European Union," German Foreign Minister Guido Westerwelle said during informal talks in Cyprus with his 26 EU counterparts.

He added, “I see a growing consensus between my colleagues. We will not accept a nuclear weapon for Iran.”

French Foreign Minister Laurent Fabius said all foreign ministers who spoke on the issue at the talks favored fresh punitive measures against Iran and that work to agree financial, trade and oil sanctions would begin "in the coming days."

The last round of EU sanctions, a damaging oil embargo, came into effect on July 1, adding to U.S. financial sanctions aimed at shutting off Iran's oil exports, which account for half of government revenues.