VIENNA, Austria - The U.N. atomic agency said for the first time Tuesday that Iran is suspected of conducting secret experiments whose sole purpose is the development of nuclear arms, an assessment that draws on 1,000 pages of intelligence and nearly a decade of research.
The report by the International Atomic Energy Agency is its most unequivocal yet suggesting that Iran is using the cover of a peaceful nuclear program to produce atomic weaponry. Based on years of trying to probe Tehran's secretive activities, its release will stoke debate on whether it's time to jettison failed diplomatic efforts to end Iran's nuclear defiance and replace them with force.
The 13-page annex to the IAEA's regularly scheduled report on Iran included evidence that suggests the Islamic republic is working on the clandestine procurement of equipment and designs to make nuclear arms.
"While some of the activities identified in the annex have civilian as well as military applications, others are specific to nuclear weapons," the report said.
Among these were indications that Iran has conducted high explosives testing and detonator development to set off a nuclear charge, as well as computer modeling of a core of a nuclear warhead. The report also cited preparatory work for a nuclear weapons test, and development of a nuclear payload for Iran's Shahab 3 intermediate range missile -- a weapon that can reach Israel.
In Washington, officials said the report confirms U.S. suspicions about the military nature of Iran's program, and the Obama administration was readying a range of sanctions and other measures against Iran should the Islamic republic fail to answer questions raised about its nuclear ambitions.
Israeli government spokesman Mark Regev said there was a government directive not to comment until Israel has studied the findings in depth.
But before the report's release, Israeli Defence Minister Ehud Barak warned of a possible Israeli military strike against Iran's nuclear program.
"We continue to recommend to our friends in the world and to ourselves, not to take any option off the table," he told Israel radio.
That phrase is often used by Israeli politicians to mean a military assault. Israeli leaders have engaged in increased saber rattling recently, suggesting that an attack was likely a more effective way to stop Iran's nuclear program than continued diplomacy.
Iran is under U.N. sanctions for refusing to stop uranium enrichment -- which can produce both nuclear fuel and fissile warhead material -- and other suspected activities that the international community fears could be used to make atomic arms. But Iran dismisses such allegations and says its activities are meant to be used only for energy or research.
Iran's official IRNA news agency dismissed the U.N. findings, accusing IAEA chief Yukiya Amano of including "worthless comments and pictures provided by the intelligence services." In Vienna, Ali Asghar Soltanieh, Iran's chief IAEA delegate, called the report "unbalanced, unprofessional and prepared with political motivation and political pressure by the United States."
In Moscow, Russia's Foreign Ministry said it would not comment until it had time to study the report carefully.
Some of the information was new -- including evidence of a large metal chamber at a military site for nuclear-related explosives testing. Iran contemptuously dismissed that, saying they were merely metal toilet stalls.
The bulk of the information, however, was a compilation of alleged findings that have already been partially revealed by the agency. It was meant to connect the dots between procurement, draftboard planning and testing, all supervised by the military under the guise of civilian organizations.
But a senior diplomat familiar with the report said its significance lay in the comprehensive way it laid out evidence indicating that Iran has engaged in all aspects of testing needed to develop a nuclear weapon. Also significant was the agency's decision to share most of what it knows or suspects about Iran's secret work with the 35-nation IAEA board and the U.N. Security Council after being stonewalled by Tehran in its attempts to probe such allegations.
It also underlined concerns that Iran had apparently continued work on developing a nuclear warhead and ways to trigger it past 2003 -- the year that a U.S. intelligence assessment in 2007 said such activities stopped. Instead, the agency said, some of this work continued at least until 2010, although in a less concentrated way.
Unusually strong language reflected such worries, with the report noting that "some of the activities undertaken after 2003 would be highly relevant to a nuclear weapons program."
"I think (the IAEA) want to lay out their case and say, 'Look, we've gone as far as we can, here's our best argument,"' said David Albright whose Institute for Science and International Security in Washington tracks suspected nuclear proliferators.
The next step, he said, was up to the IAEA's decision-making board, which referred Iran to the U.N. Security Council in 2006 -- and can do so again, strengthening the chances of new U.N. sanctions.
The report was not being viewed as a game-changer in Washington. It doesn't reveal intelligence unknown to the United States -- which contributed to much of the IAEA's knowledge about Iran's nuclear work -- and U.S. officials said it is unlikely to persuade reluctant powers such as China and Russia to support tougher sanctions on the Iranian government.
But the officials, who asked for anonymity because their information is privileged, said the report offered significant support for some long-held U.S. suspicions and lends international credence to claims that Tehran isn't solely interested in developing atomic energy for peaceful purposes.
A senior administration official said the finding that Iran undertook computer modeling of the core of a nuclear bomb was "of particular concern."
"There is no application of such studies to anything other than a nuclear bomb," the official said.
The official also pointed to the report's assessment that Iran is developing fast-acting detonators that can be used in a nuclear weapon, and its efforts to procure key nuclear weapons ingredients, such as high-speed electronic switches, spark gaps, high-speed cameras, neutron sources and radiation detection and measuring equipment.
The Obama administration will use the report as leverage in making its case to other countries that sanctions against Iran should be expanded and tightened, and that the enforcement of current sanctions be toughened, the officials said.
However, it's not going to sway the U.S. administration from its plan to rely on sanctions and diplomatic pressure, instead of military threats, to deter Iranian ambitions, they said.
The U.N. Security Council has passed four sets of damaging sanctions on Iran, but veto-wielding members China and Russia oppose further measures and are unlikely to change their minds despite the report's findings.
