Iran said on Sunday it will boost its uranium enrichment in a few hours above a cap set by a landmark 2015 nuclear deal, a move that could eventually culminate in the return of all international sanctions on Tehran, reported Reuters.
In a sign of heightening Western concern, French President Emmanuel Macron condemned Iran's decision as a "violation" of the pact which the United States pulled out of last year.
Raising the prospect of fresh regional tensions, Israeli Prime Minister Benjamin Netanyahu said the step was extremely dangerous and he again called on Europe to impose punitive sanctions on Tehran.
In a live news conference, senior Iranian officials said Tehran would keep reducing its commitments every 60 days, unless signatories of the pact protect it from US sanctions imposed by President Donald Trump.
"We are fully prepared to enrich uranium at any level and with any amount," said Behrouz Kamalvandi, spokesman for Iran's Atomic Energy Organisation.
"In a few hours the technical process will come to an end and the enrichment beyond 3.67% will begin," referring to the limit set in the 2015 agreement.
But Iran said it was willing to show flexibility.
All measures taken by Iran to scale back its commitments to the nuclear deal were "reversible" if the European signatories of the pact fulfilled their obligations, Foreign Minister Mohammad Javad Zarif tweeted on Sunday.
Netanyahu called for a strong response.
"The enrichment of uranium is made for one reason and one reason only – it's for the creation of atomic bombs," said the Israeli prime minister, a vocal opponent of the 2015 agreement.