Updated

Iran says the U.S. and its allies provided false information saying Tehran's missile and explosives experiments were part of a nuclear weapons program, the International Atomic Energy Agency said Friday.

As expected, an IAEA report also confirmed that Iran continued to enrich uranium despite two sets of U.N. Security Council sanctions to punish it for defying council demands to freeze the program, which can generate both nuclear fuel and the fissile core of warheads.

That set the stage for a third set of sanctions, although permanent council members Russia and China will likely oppose tough new measures.

The 11-page report obtained by The Associated Press gave Iran a relatively clean bill of health on explaining the origin of traces of enriched uranium in a military facility; experiments with polonium, which can also be used in a weapons program; and purchases on the nuclear black market.

In such cases, "the agency has been able to conclude that answers provided by Iran ... are (either) consistent with its findings (or) ... not inconsistent with its findings," said the report, in careful language that would allow it to renew its investigation into the issues.

But it said Teheran had rejected as irrelevant some material forwarded by the agency that purportedly shows it working on tests of missile trajectories and high explosives, and research on a missile re-entry vehicle — activities that would most likely be part of weapons development. Questions also remained on how and why Iran came to possess diagrams showing how to mold uranium metal into warhead shape.

Such "weaponization" themes remain "the one major remaining (unresolved) issue relevant to the nature of Iran's nuclear program," said the report. It noted that among the evidence reviewed — and rejected as irrelevant by Tehran — were diagrams showing a missile re-entry vehicle that would be "quite likely ... able to accommodate a nuclear device."

Iran's dismissal was sure to be found unacceptable by the United States, which diplomats say provided most of the material that led in recent months to an accelerated IAEA investigation of Iran's purported weapons program activities.

Ahead of the confidential report's release to the 35-nation IAEA board and the U.N. Security Council, U.S. officials had repeatedly insisted that the IAEA probe would be incomplete unless Iran acknowledged trying to make nuclear arms in the past. That stance is shared by Canada, Japan, Australia and U.S. allies in Europe.

A senior IAEA official, who demanded anonymity as a condition of discussing the report, said that if the material provided by the U.S. and other agency members on the alleged activities was genuine, most of Iran's work was "most likely for nuclear weapons." But he said the agency was not reaching any conclusion until the Iranians went beyond rejection of the purported evidence and concretely addressed the issues it raised.