Report Sets Stage For Action on Iran

Iranian President Mahmoud Ahmadinejad gestures to a crowd during a public gathering in Khorramdareh, Iran, on Friday. (AP)

The resolution would not explicitly threaten sanctions against Iran if it failed to comply. However, U.S. and European diplomats would seek to invoke Chapter 7 of the U.N. Charter, which has traditionally been used to justify sanctions or military action.

"The Security Council is going to have to raise the costs to the Iranians," Undersecretary of State R. Nicholas Burns said in an interview. Burns is to meet Tuesday in Paris with top officials from Russia, China, Britain, France and Germany to discuss the next steps in the council and prepare for a meeting of foreign ministers on Iran on May 9 in New York.

"This is leading toward a sanctions regime," Burns said. "We won't get there in the next two or three weeks, but this has to be the course of actions." He called on Iran's major trading partners to halt business with the country and to cancel pending weapons sales.

The report, issued by IAEA Director General Mohamed ElBaradei after inspectors from his agency visited Iranian facilities again, revealed few new details about the program. But it expressed growing frustration over Iran's efforts to stonewall the inspectors.

"After more than three years of Agency efforts to seek clarity about all aspects of Iran's nuclear program, the existing gaps in knowledge continue to be a matter of concern," the report says. "Any progress in that regard requires full transparency and active cooperation by Iran."

The agency's toughest complaint concerned Iran's failure to provide a credible explanation for where it obtained materials used for small-scale experiments with plutonium. Plutonium separation is a process that can be used in weapons development.

"The agency cannot exclude the possibility -- not withstanding the explanations provided by Iran -- that the plutonium analysed by the agency was derived from source(s) other than the ones declared by Iran," the report says.

The report says that in addition to the 164 centrifuges Iran was previously reported to be using in uranium enrichment experiments, two additional 164-centrifuge systems known as cascades are under construction, an indication that Iran is trying to step up its experiments.

Officials with knowledge of the Iranian program, speaking on condition of anonymity because of the sensitivity of the subject, said that several centrifuges had crashed during the enrichment run last month and that the Iranians had cut many corners in a rush to demonstrate technical prowess.

The IAEA said Iran had refused to provide any explanation of public statements by Iranian officials concerning the testing of centrifuges known as P-2 models, which can enrich uranium more quickly and efficiently than the P-1 centrifuges currently in use can.

In addition, inspectors reported that since September, Iran has produced 110 tons of UF6, a key product used in the enrichment process. That is a higher amount than previously recorded.

Nuclear experts generally say Iran's program does not pose any immediate dangers to the outside world. "If they don't have a plant that is able to operate for a significant time, then this doesn't pose a near- or mid-term threat," said Michael Levi, a nuclear expert at the Council on Foreign Relations.

But many experts are concerned that the capabilities gained from experiments -- even those done under the monitoring of the IAEA -- could help Iran conceal the rate of progress in its program.

"Conducting open experiments with uranium enrichment teaches you how to more effectively hide that work, avoid accidents and control emissions that might give away the program," Levi said. He called Iran's ability to enrich uranium to 3.6 percent purity, as outlined in the report, an achievement.

Linzer reported from Washington. Staff writer Colum Lynch in New York contributed to this report.