Vienna International Centre, where IAEA offices are located
Vienna International Centre, where IAEA offices are locatediStock

Iran has started enriching uranium at its underground Natanz plant with a second type of advanced centrifuge, the IR-4, the International Atomic Energy Agency (IAEA) said in a report obtained by Reuters on Tuesday.

The move is yet another breach by Iran of the nuclear deal it signed with major powers in 2015.

“On 15 March 2021, the Agency verified that Iran began feeding the cascade of 174 IR-4 centrifuges already installed at FEP with natural UF6,” the IAEA said in the report to member states dated Monday, referring to uranium hexafluoride, the form in which uranium is fed into centrifuges for enrichment.

Iran has consistently scaled back its compliance with the 2015 deal in response to former US President Donald Trump’s withdrawal from it in 2018.

The IAEA last month reported that Iran had added 17.6 kilograms (38.8 pounds) of uranium enriched up to 20% to its stockpile as of February 16.

Iran also increased its total enriched uranium stockpile to 2,967.8 kilograms (6,542.9 pounds), up from 2,442.9 kilograms (5,385.7 pounds) reported on November 2, the IAEA said.

As part of its moves to reduce compliance with the 2015 nuclear deal, the Islamic Republic recently ended the implementation of the Additional Protocol of the 2015 nuclear deal that allows the IAEA to carry out snap-inspections at sites not declared to the agency.

IAEA chief Rafael Grossi later visited Tehran, however, where he reached a deal with Iran to continue some verification and monitoring activities in the country.