By Mark Heinrich
Iran said an International Atomic Energy Agency inquiry into its nuclear activity was at a dead-end because the IAEA was demanding Tehran reveal conventional military secrets without nuclear dimensions. Iran has denied seeking atom bombs.
The Vienna-based U.N. watchdog said in a report on Monday that Iranian stonewalling had brought an agency inquiry to resolve whether Tehran had covertly researched ways to make a nuclear bomb to a standstill.
Britain has accused Iran of showing contempt for the U.N. watchdog and, with the United States and France, vowed to seek harsher sanctions on Tehran over its defiance of U.N. demands for full disclosure and a suspension of uranium enrichment.
The IAEA wants Iran to clarify intelligence material pointing to links between Iranian projects to process uranium, test high explosives and modify the cone of its long-distance Shahab-3 missile in a way suitable for a nuclear warhead.
The Islamic Republic has denied the allegations but the IAEA says Iran must substantiate its position by granting access to sites, documents and relevant officials for interviews.
Herman Naeckerts, the agency's head of inspections in the Middle East region, briefed its governing board on the report's findings on Tuesday ahead of a meeting by the 35-nation body next week likely to heighten pressure on Iran to cooperate.
Washington's IAEA envoy said Naeckerts presented photos and diagrams of Iranian work on re-designing a Shabab-3 "to carry what would appear to be a nuclear weapon".
"VERY CREDIBLE"
"The (IAEA) Secretariat told us the information they have is in their words, 'very credible', unquote, and they have asked Iran to provide 'substantive responses', unquote," Ambassador Gregory Schulte told reporters.
He said Naeckerts told the closed meeting Iran had refused IAEA requests to interview engineers involved in the work and visit their ostensibly civilian workshops, depicted in photos.
Other diplomats in the meeting said Naeckerts emphasised the information remained unverified. "His presentation was professional and balanced," one said, asking for anonymity.
Another diplomat said some countries on the board questioned the IAEA's mandate to judge intelligence data related to ballistic missiles and high explosives.
Iran repeated that the intelligence was forged or pertained only to conventional arms. It said Iran faced extraordinary and unacceptable pressure to prove unverified allegations were wrong by revealing information vital to its national security.
"No country would give information about its conventional military activities," Iran's IAEA ambassador said.
"I said in this briefing, 'Who in the world would believe there are a series of top secret documents U.S. intelligence found in a laptop regarding a Manhattan Project-type nuclear (bomb programme) in Iran and none of these documents bore seals of 'high confidential' or 'secret'?" Ali Asghar Soltanieh said.
"This matter is over, as far as we are concerned."
Western concern was heightened by a revelation in the IAEA report that Iran may have had "foreign expertise" helping in experiments on a detonator applicable to an implosion-type nuclear blast occurring at high altitude.
Informed diplomats said the expertise appeared not to have been given by a government such as North Korea or any remnants of the ex-A.Q. Khan nuclear smuggling network that supplied Iran in the past, but by other non-state actors.
The IAEA has called for an explanation from Iran.
(Editing by Ralph Boulton)
