The European Union, France, Germany and Britain have said on 11 November that they are “extremely concerned” by Iran’s decision to re-start nuclear activities at one of its key sites, in breach of the 2015 nuclear deal, and warned they might take action against Tehran.

In its latest report on Iran on 11 November, the International Atomic Energy Agency said it has detected uranium particles at an undeclared site in Iran, and confirmed that it has ramped up uranium enrichment, with its stockpile now reaching the equivalent of 551 kilograms, as opposed to the 300-kilogram limit laid down in the deal. The report concluded that Iran has prepared a new facility for testing enrichment centrifuges.

“The Foreign Ministers of France, Germany and the United Kingdom and the High Representative of the European Union are extremely concerned by the latest announcements that Iran is restarting uranium enrichment activities at the Fordow facility, as confirmed by the International Atomic Energy Agency (IAEA) in its November 11 report,” EU and the three countries said in a joint statement.

“We underline the importance of the full and effective implementation of the JCPOA by all sides and confirm our determination to continue all efforts to preserve the agreement, which is in the interests of all,” the statement reads.

Iran has repeatedly warned the remaining parties to the deal that the agreement can only be rescued if they help the country avoid US sanctions.