The International Atomic Energy Agency (IAEA) said in a report on Saturday that Iran has escalated its uranium enrichment further by enriching with advanced machines at its underground Fordow plant.
The machines are said to be able to switch more easily between enrichment levels.
The confidential IAEA report to member states said that the UN atomic watchdog verified on Saturday that Iran had begun feeding uranium hexafluoride gas enriched to up to five percent into the cascade, or cluster, of 166 IR-6 centrifuges with so-called modified sub-headers at Fordow.
The report indicates that Iran has informed the IAEA it plans to use the machines to enrich to up to 20 percent purity, which is less than the up to 60 percent it is producing elsewhere and the roughly 90 percent weapons-grade.
Due to making it possible to switch to higher purity levels much more easily and quickly, Western diplomats have repeatedly expressed concern about the modified sub-headers.
