WASHINGTON — In recent meetings with U.N. weapons inspectors, Iranian officials rejected as "fabricated" top-secret evidence that U.S. officials have said proves that Iran has tried to develop advanced nuclear weapons, the U.N.'s nuclear watchdog said Friday.
The evidence was gleaned largely from a laptop computer that was spirited out of Iran in 2004 and obtained by U.S. intelligence agencies.
The laptop's contents have been in the hands of the U.N.'s International Atomic Energy Agency since the summer of 2005, but it was only in late January that the United States and other countries authorized the IAEA to show some of the evidence to Iran. Further evidence was shared with Iran in a Feb. 15 meeting.
"Iran stated that the allegations were baseless and that the information which the agency had shown to Iran was fabricated," said the IAEA's confidential 11-page report, which was available on the Web site of the Institute for Science and International Security, a nonpartisan Washington policy research organization.
The IAEA's widely anticipated report offered a mixed assessment of Iranian cooperation with nuclear inspectors that was unlikely to resolve the international stalemate over Iran's nuclear program.
The report said that the IAEA still couldn't provide "credible assurances" that Iran isn't hiding nuclear material or programs from inspectors.
But it added that since its last report in November, Tehran has provided clarification of some of its past nuclear activities. It also said that despite Iran's continued enrichment of uranium in defiance of the Security Council, there's no concrete evidence that it's pursuing a nuclear weapon.
Iran has insisted that its nuclear program is intended to develop civilian nuclear power, not weapons.
A U.S.- and European-led effort to impose new sanctions on Iran has faltered in the face of Russian and Chinese opposition. It was further hobbled by a U.S. National Intelligence Estimate in November, which said that Iran had halted a covert nuclear weapons program in the fall of 2003.
IAEA Director General Mohamed ElBaradei, who frequently has been at odds with the Bush administration, said that in the last four months, the agency has made "quite good progress" in untangling Iran's nuclear research, which it had kept hidden for nearly 20 years.
ElBaradei said that the one exception was Iran's alleged study of weaponization, the process of turning nuclear weapons material into a warhead capable of being launched at a target.
The United States and Britain both said that the IAEA report showed that Iran is continuing to defy the United Nations.
"Iran has not suspended its (uranium) enrichment and other proliferation-sensitive activities as required by the Security Council; it has not explained detailed activities which the agency believes would be relevant to nuclear weapon research and development; nor has it allowed IAEA inspectors to verify that these activities are stopped," said Ambassador Gregory Schulte, the U.S. representative to the IAEA.
The allegations that Iranian scientists conducted nuclear weaponization studies have long been controversial. While attention has focused largely on the laptop, officials familiar with the U.S. case say evidence also has come from other countries.
Little is known about how American intelligence agencies got the laptop. The work found on it appears authentic, said David Albright, a nuclear expert and the president of the Institute for Science and International Security. But Albright said it's also incomplete and, in some cases, shoddy.
U.S. officials say the information on the laptop suggests that Iran has worked on designing a missile re-entry vehicle that would house a nuclear warhead; made plans to conduct underground nuclear weapons-related testing; and studied how to produce a substance known as uranium tetrafluoride, a step in the purification of uranium that can be used in a bomb.
On Iran's current nuclear work, the report also painted a mixed picture.
It said that Iran appears to be having technical trouble operating a chain of 3,000 centrifuges, fast-spinning machines designed to produce enriched uranium that can be used to generate electricity or, at high concentrations, in a nuclear weapon.
But the report also disclosed that Iran has begun installing a new generation of advanced centrifuges at its Natanz nuclear facility.