VIENNA, Austria -- A Western push to deny Iran technical help in building a plutonium-producing reactor has gathered enough support to be approved by the 35-nation board of the U.N. nuclear watchdog agency, diplomats said Sunday.

Still, differences both within the Western camp and more broadly among different factions on the International Atomic Energy Agency on how harshly to punish Iran for its nuclear defiance persisted on the eve of the opening meeting today, said the diplomats.

Normally, the United States takes the lead in demanding tough action against Tehran for defying U.N. Security Council demands that it freeze uranium enrichment, a possible pathway to nuclear arms.

But with council agreement on sanctions mired down because of Russian and Chinese efforts to block tough punishment, diplomats said the Americans have taken a back seat to the France at the upcoming Vienna meeting in calling for harsher penalties.

Like, their European allies, the Americans were calling for Iran's request for help in building the Arak research reactor to be denied when the IAEA board meets in committee starting today -- and later in the week in full conference to formally approve committee decisions.

But France was demanding even more, said the diplomats -- all accredited to the IAEA, who demanded anonymity in exchange for discussing strategies ahead of the meeting. They said Paris was asking the IAEA to probe the seven other projects Iran had submitted individually -- and possibly reject any or all of them, if they were found to be risks to nuclear proliferation.

Even countries traditionally supportive of Iran were likely to want to deny some help to Iran -- probably through a compromise that defers a decision on the issue. Both the Security Council and the IAEA board have issued resolutions urging Tehran to stop construction of the facility.

Arak produces plutonium waste, which, like enriched uranium, can be used for warheads, but the other seven projects that Iran has asked help with are less problematic.

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 agreed does not pose a threat to nuclear proliferation.

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, France would likely be forced to modify its position once the meeting opened, the diplomats said.

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.