Iran said it had almost doubled its stock of enriched uranium in less than a month, as it prepared to resume talks with world powers on curbing its nuclear programme.
Tehran has progressively abandoned its commitments to a 2015 nuclear deal since former US president Donald Trump pulled Washington out in 2018 and imposed strict sanctions.
"We have more than 210 kilograms of uranium enriched to 20 per cent, and we've produced 25kg at 60 per cent, a level that no country apart from those with nuclear arms are able to produce," Atomic Energy Organisation of Iran spokesman Behrouz Kamalvandi told state news agency Irna late on Wednesday.
In September, the International Atomic Energy Agency confirmed that Iran had boosted its stocks of uranium enriched above the level allowed in the deal.
On October 10, Iran's atomic energy chief Mohammed Eslami said his country had produced more than 120kg of 20 per cent enriched uranium, in theory allowing it to make medical isotopes used mainly in diagnosing certain cancers.
Iran was not meant to enrich uranium above 3.67 per cent, well below the 90 per cent needed for use in a nuclear weapon.
The 2015 agreement with Britain, China, Russia, France, Germany and the US offered Iran some sanctions relief in return for curbs on its nuclear programme.
Nuclear negotiations between Iran and world powers are to resume on November 29. Iran has insisted its nuclear program is for peaceful purposes.