The European Union has strongly urged Iran to reverse its decision to raise the level at which it enriches uranium beyond that allowed by a 2015 nuclear deal.
Spokeswoman Maja Kocijancic said the bloc was extremely concerned after Iran announced that it was producing material with a fissile purity of 4.5%. European leaders fear it could speed up the potential development of a nuclear weapon, something Iran denies seeking.
Iran has said it is responding to sanctions the United States reinstated last year.
The country has also accused European powers of failing to protect its economy from the sanctions’ effects and insisted that its actions are in line with the deal known formally as the Joint Comprehensive Plan of Action or JCPOA.
It has promised to keep reducing its commitments every 60 days unless it begins to see the accord’s promised benefits, and warned the Europeans that “certain strange acts” will prompt it to “skip all the next steps” and implement the final one.
The five other parties to the deal, the UK, France, Germany, Russia and China could refer the issue to a “joint commission”, a process that could ultimately lead to the “snap back” of the UN and multilateral sanctions lifted three years ago.