The deal bans nuclear material from Fordow, and with the gas entering its centrifuges the facility will move from a permitted status of research plant to being an active nuclear site
Iran has stepped up work at its underground Fordow nuclear facility, state TV reported on Wednesday, a move France said showed for the first time that Tehran explicitly planned to quit a deal with world powers that curbed its atomic work.
Russia also voiced alarm at Iran's decision to start injecting uranium gas into centrifuges at Fordow, a move that further distances Iran from the accord. A central aim of the agreement was to extend the time Iran would need to build a nuclear weapon, if it chose to, to a year from about 2-3 months.
"With the presence of inspectors from International Atomic Energy Agency, Iran started injecting uranium gas into centrifuges in Fordow," TV reported.
The deal bans nuclear material from Fordow, and with the gas entering its centrifuges the facility will move from a permitted status of research plant to being an active nuclear site.
A spokesman for Iran's Atomic Energy Organization, Behrouz Kamalvandi, however told state TV later that the injection of uranium gas would start at 2030 GMT.
"We have put the 2,800kg cylinder including 2000kg uranium hexafluoride (UF6) that has been put in Fordow . The centrifuges there will enrich uranium up to 4.5% level," Kamalvandi said.
President Hassan Rouhani, architect of the deal, blamed the Washington for Iran's rolling back of its nuclear commitments, saying Fordow would soon fully resume uranium enrichment work.
"Iran's 4th step in reducing its commitments under the JCPOA the 2015 nuclear deal by injecting gas to 1,044 centrifuges begins today. Thanks to US policy and its allies, Fordow will soon be back to full operation," Rouhani tweeted.
Speaking on a visit to China, French President Emmanuel Macron called Iran's move "grave", saying it explicitly signalled Iran's intent for the first time to quit the deal.
"I think that for the first time, Iran has decided in an explicit and blunt manner to leave the JCPOA nuclear agreement, which marks a profound shift," said Macron, who has been at the forefront of European efforts to salvage the deal after the United States withdrew from the agreement.
In Moscow, Russian Foreign Minister Sergei Lavrov said events unfolding around the nuclear deal were extremely alarming and called on Iran to fulfill the terms of the deal.
But he added that Moscow understood why Tehran was cutting back on its commitments, and blamed the situation on the US decision to pull out of the pact.
Iran agreed in 2015 to turn Fordow into a "nuclear, physics and technology centre" where 1,044 centrifuges are used for purposes other than enrichment, such as producing stable isotopes, which have a variety of civil uses.
Last year, US President Donald Trump exited the deal and said it was flawed in Iran's favour. Washington has since renewed and intensified its sanctions, slashing Iran’s economically vital crude oil sales by more than 80%.
Responding to Washington’s "maximum pressure" policy, Iran has bypassed the restrictions of the deal step-by-step - including by breaching both its cap on stockpiled enriched uranium and on the level of enrichment.
"Iran has taken its fourth step to decrease its nuclear commitments to the deal in reaction to the increased US pressure and inactivity of European parties to the deal to save it," state TV added.