A push by Western nations 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 UN nuclear watchdog agency, diplomats said. 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 Monday, the diplomats said. Normally, the United States takes the lead in demanding tough action against Tehran for defying UN 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 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 turned down when the IAEA board meets in committee starting Monday - and later in the week a full conference to formally approve committee decisions.