Iran nuclear chief says 60% uranium enrichment started at Natanz site

Iran has begun 60 per cent uranium enrichment at its Natanz plant, the country's nuclear chief said on Friday, days after an explosion at the site that Tehran blamed on Israel.

"We are producing about nine grams of 60 per cent enriched uranium an hour," said Ali Akbar Salehi, head of the Atomic Energy Organization of Iran. "But we have to work on arrangements to drop it to five grams per hour."

Earlier, parliament speaker Mohammad Qalibaf said Iranian scientists had successfully started enriching 60 per cent uranium at 12:40 a.m. local time.

"The will of the Iranian nation makes miracles that thwart any conspiracy," Qalibaf said on Twitter.

In Vienna, a spokesperson for the International Atomic Energy Agency (IAEA), the United Nations nuclear watchdog,  declined to comment on the Iranian statements about 60 per cent enrichment.

Iran has said its decision to increase enrichment to its highest level ever was in response to sabotage at its key nuclear site at Natanz on Sunday by Israel.

Iran and global powers are meeting in Vienna to try to rescue a 2015 nuclear deal abandoned by Washington three years ago, in an effort potentially complicated by Tehran's decision to ramp up uranium enrichment.

The 2015 agreement sought to make it harder for Iran to develop an atomic bomb — something it denies ever trying to do — in return for lifting sanctions.

Abbas Araqchi, Iran's chief nuclear negotiator at the nuclear talks in Vienna, said earlier this week that Iran would activate 1,000 advanced centrifuge machines at Natanz.

An Iranian official told Reuters that "60 per cent enrichment will be in small quantity" only.

Multiple Israeli media outlets have quoted unnamed intelligence sources as saying the country's Mossad spy service carried out the sabotage operation at the Natanz complex.

Israel — widely believed to be the only Middle Eastern country with a nuclear arsenal — has not formally commented on the incident.