VIENNA - Diplomats say Iran is on the threshold of boosting output of material that can be turned into weapons grade uranium used in nuclear warheads.
One diplomat tells The Associated Press that Tehran is now technically ready within days to ramp up its production of 20-per cent enriched uranium by nearly 700 centrifuges.
That would nearly double present output at Iran's heavily fortified Fordo enrichment plant.
Two other diplomats could not confirm the 700 number but said Tehran has put a sizeable number of centrifuges at Fordo that were previously installed but not ready to operate under vacuum.
It takes only a few days to begin enrichment with machines that are under vacuum.
Iran denies wanting nuclear arms. The diplomats demanded anonymity Thursday because they were not authorized to discuss the issue.