Iran's stock of uranium enriched to up to 60%, close to weapons-grade, has grown to enough, if enriched further, for a nuclear bomb, a report by the United Nations nuclear watchdog showed on Wednesday.

Passing that threshold is a milestone in the unraveling of the 2015 nuclear deal between Iran and world powers, which capped the purity to which Iran was allowed to enrich uranium at 3.67%, well below the 20% it achieved before the deal and the roughly 90% that is weapons grade.

Washington's withdrawal from the deal under then-President Donald Trump and its reimposition of sanctions against Tehran that had been lifted under the deal prompted Tehran to breach the deal's nuclear restrictions.

"Iran now can produce 25 kg (of uranium) at 90% if they want to," a senior diplomat said in response to Wednesday's International Atomic Energy Agency report seen by Reuters when asked if Iran had enough material enriched to 60% for one bomb.

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