Ali Ashgar Soltanieh, Iran's chief delegate to the IAEA, said as much again Monday, telling The Associated Press that the report described "the peaceful nature of our nuclear actions".

"The Americans failed ... in shameful attempts" to co-opt the agency into delivering anti-Iranian findings, he said.

He noted a paragraph in the report saying that agency experts had been given access to all declared nuclear material in Iran and verified that all of it was accounted for.

But Gregory L. Schulte, his US counterpart, suggested the report was a strong indictment of Iran's defiance of the international community's efforts to get answers about troubling parts of its nuclear program, noting it "details a long list of questions that Iran has failed to answer."

"At the same time that Iran is stonewalling its inspectors, it's moving forward in developing its enrichment capability in violation of Security Council resolutions," Schulte said.

He described parts of the report as a "direct rebuttal" of Iranian claims that all nuclear questions had been answered.

US intelligence says Iran stopped work on nuclear weapons in 2003 but some other nations believe such activities continued past that date. The report noted Iran continued to deny such allegations.

Obtained by the AP, the restricted report forwarded to the UN Security Council and to the 35 board members of the IAEA said Iran remains defiant of the council's demands that it suspend uranium enrichment.

Shrugging off three sets of council sanctions, Iran has expanded its operational centrifuges – machines that churn out enriched uranium – by about 500 since the last IAEA report, in February, the new report said.

In announcing major progress in his government's push for nuclear power, Iranian President Mahmoud Ahmadinejad said last month that Iranian scientists were putting 6,000 new uranium enriching centrifuges into place and testing a new type that worked five times faster.

The IAEA report noted Iran now had only 3,500 centrifuges and said the few advanced machines actually running were only in a testing phase. Still the senior UN official said Iran's goal of 6,000 machines running by the summer was "pretty much plausible".