The European Union said yesterday it was “extremely concerned” by Iranian plans to breach the uranium enrichment cap set by the 2015 nuclear deal, calling on Tehran to reverse course.

Iran said Sunday it would breach the cap “in a few hours” and on Monday announced it had passed 4.5 percent enrichment—well above the 3.7 percent limit.

It first announced its intention to reduce compliance with the deal in May, a year after US President Donald Trump unilaterally withdrew from the pact and reimposed crippling sanctions.

“We strongly urge Iran to stop and reverse all activities that are inconsistent with the commitments made under the JCPOA,” EU spokeswoman Maja Kocijancic told reporters.

The JCPOA or Joint Comprehensive Plan of Action gave Iran relief from punishing sanctions in return for setting strict limits on its nuclear activities.

The remaining signatories—Britain, France, Germany, Russia and China—say the deal is the best way to stop Iran developing atomic weapons.

“We are extremely concerned by the announcement made over the weekend by Iran regarding the start of the uranium enrichment above the limit of 3.7 percent,” Kocijancic said.

The EU will await a report from the UN’s atomic energy authority and consult other signatories to the deal before deciding on future steps, Kocijancic said.

Britain, France and Germany have sought to save the deal by creating special mechanism called INSTEX to sidestep US sanctions so Iran can keep trading.

But the mechanism is still not operational six months after its launch and Tehran has grown increasingly frustrated at Europe’s failure to act effectively.

Brussels officials see the latest announcements from Iran as a bid to pressure the West into doing more to help. “The situation is extremely difficult for them domestically—they are running out of humanitarian supplies,” an EU source told AFP. “They want to preserve the agreement, but they want the benefits they were promised.”

The steps Iran has taken so far—increasing enrichment and breaching a limit on uranium reserves—can be reversed, the source said.

However, if Iran went above five percent enrichment, the situation would be more serious, officials warn.

Iran warned European countries on Monday against any escalatory response to its move to breach the uranium enrichment cap set by a landmark 2015 nuclear deal.

If European parties to the agreement “do certain strange acts then we would skip all the next steps (in the plan to scale back commitments) and implement the last one,” foreign ministry spokesman Abbas Mousavi said. He did not specify what the final step would be.

Iran said Sunday it was hours away from breaching the uranium enrichment limit, stepping back from another commitment more than a year after the United States pulled out of the nuclear accord. Asked if Tehran could withdraw entirely from the deal, Mousavi said “all the options” were possible but “no decision has been taken”.