Thirty five nations abruptly adjourned a meeting Monday focusing on Iran's request to the UN nuclear watchdog agency for help in building a plutonium-producing reactor, reflecting discord despite general agreement on denying such aid.
Adding to potential conflict was a ruling by the UN organization - the International Atomic Energy Agency - that the reactor, as well as seven other project Iran is seeking IAEA help for, did not pose a proliferation threat.
"These projects do not contribute to enrichment related or reprocessing activities in Iran," Anna Maria Cetto, an agency deputy director general, told a closed IAEA committee meeting reviewing technical aid requests from Iran and other countries ahead of a full board session starting Thursday.
"All (Iranian) projects are in conformity with" Security Council action focused on wresting agreement from Iran to freeze programs that could be used to make nuclear weapons, she said in remarks made available to reporters.
The main council concern is Tehran's uranium enrichment program - and Iran's defiance of a council demand that it freeze such activities. But the Arak heavy water reactor is also worrying because once it is completed - sometime in the next decade - it will produce plutonium. This, like highly enriched uranium, can be used for the fissile core of nuclear warheads.
Despite Cetto's ruling, most of the IAEA's 35 board nations feel that Iran should not be given any kind of agency help in constructing the Arak reactor, diplomats said. But positions diverge on other projects that Tehran has submitted to the agency.
The adjournment until Monday afternoon was decided on in order to give time for board members to agree on a common position in informal discussions outside the meeting, said diplomats who participated in the closed gathering.
Normally, the United States takes the lead in demanding tough action against Tehran for defying UN Security Council demands that it freeze uranium enrichment.
But with council agreement on sanctions mired down because of Russian and Chinese efforts to block severe punishment, diplomats said the Americans have taken a back seat to France in calling for harsher penalties at the Vienna meeting.
Like their European allies, the Americans were calling for the IAEA to turn down Iran's request for help in building the Arak research reactor.
But going into the meeting, France had been demanding even more, said the diplomats - all accredited to the IAEA. They demanded anonymity in exchange for discussing strategies.
They told The Associated Press that before the ruling by Cetto, Paris had been asking the IAEA secretariat to probe the seven other projects Iran had submitted individually - and possibly reject those found to possibly encourage nuclear proliferation.
Even nonaligned nations traditionally supportive of Iran were likely to approve some form of denying Iran help for Arak - probably through a compromise deferring a decision on the issue instead of outright rejection.
That's because the IAEA board has issued resolutions urging Tehran to stop construction of the facility. Western nations also are pushing for any new Security Council resolution to demand that Iran stop work on Arak.
But the other seven projects that Iran has asked for help with are less controversial. One asks for help in developing nuclear capabilities for medical use. Another seeks legal help for the Russian-built Bushehr reactor, which even the Americans have accepted as not posing a threat to nuclear proliferation. And the five others ask for assistance in administrative or safety aspects of nuclear power, according to a list made available to the AP.
With most nations backing approval of all other projects except Arak - and the IAEA ruling it did not qualify as a proliferation threat - France was likely to modify its position.
Denying Iran help with Arak - where it is seeking agency assistance to make sure the reactor is environmentally safe - would do little to slow construction of that facility, expected to be completed within the next decade. And it would not affect Tehran's other potential avenue to weapons production - uranium enrichment.
Still, it would send a signal in how harshly to penalize Tehran and allow the West to continue exerting some pressure during the council deadlock.
Ali Ashgar Soltanieh, Iran's chief delegate to the IAEA, said his country's request would benefit the international community by increasing outside involvement in Arak.
"By adopting this project, the agency's presence ... will be much more," he told reporters. "Every detail and step of this project will be under ... IAEA" oversight.
A diplomat familiar with the U.S. stance said the Americans were not backing the French because of recognition that the board would agree to nothing more than denying Iran help with Arak.
Others pointed to recent changes in the top echelons of the French government agencies dealing with Iran and proliferation threats, saying new, more hardline leadership could explain why Paris was out front in seeking tougher action.