France, Britain and Germany have met a key US demand by drafting a UN nuclear resolution that sets a November deadline for Iran to dispel worries it has a covert atom bomb programme, diplomats said on Saturday.
But the draft does not order Tehran to be automatically reported to the UN Security Council if it does not meet the date, as Washington would have wished.
A Western diplomat who follows the UN International Atomic Energy Agency (IAEA) read parts of the draft text, which will be revised before being formally submitted to the IAEA board of governors, to Reuters over the telephone.
"The resolution calls upon the IAEA to make some kind of final assessment in November" on whether it is sufficiently convinced that Tehran is not secretly diverting nuclear resources to a weapons programme, the diplomat said.
Washington accuses Iran of developing nuclear weapons under cover of an atomic energy programme, a charge Iran vehemently denies. The IAEA has found many previously concealed nuclear activities in Iran but no "smoking gun" backing the US view.
US officials had been pushing the European Union's big three states to give up their strategy of trying to persuade Iran to abandon uranium enrichment and plutonium reprocessing and get tough with Iran. But diplomats in Vienna said Washington has few supporters of an immediate Security Council report.
Washington wanted the Europeans to include a "trigger mechanism" in the text. The diplomat said the draft did not have an overt "trigger mechanism" that would automatically require the IAEA board to report Iran to the Security Council in November.
Instead, he said, it calls for the board to consider whether "further steps" are needed, but in no way requires it to report Tehran to the Security Council, something the Europeans believe would be counterproductive at the present time.