BRUSSELS (Reuters) - Germany, Britain and France should be ready to consider starting moves to reinstate international sanctions on Iran over breaches of its 2015 nuclear deal, Germany’s foreign minister said on Monday.

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Europe’s position is vital as the United States has withdrawn from the deal and the other signatories, Russia and China, are allies of Iran and unlikely to start the process under which sanctions could be reimposed.

Iran said last week it had resumed low-grade uranium enrichment at its underground Fordow nuclear plant, and at the weekend said it could refine up to 60% of fissile purity, not far off the 90% level needed for nuclear bomb fuel.

“Iran must finally return to its commitments (under the 2015 accord),” German Foreign Minister Heiko Maas said before a meeting of European Union foreign ministers in Brussels.

“Otherwise we will reserve the right to use all mechanisms specified in the deal (for sanctions to be reimposed),” he said,

Under the deal, meant to reduce the scope for Tehran to develop nuclear weapons, Iran agreed to curb its nuclear programme in exchange for the removal of most international sanctions.

Tehran says its latest steps have been driven by Washington’s withdrawal from the deal and its revival of U.S. sanctions that have strangled Iran’s oil exports. Tehran says it would return to compliance if Washington did so.

“MORE AND MORE DIFFICULT” TO SAVE DEAL

EU foreign policy chief Federica Mogherini said she was contacting the signatories to decide what to do next. EU ministers did not discuss sanctions on Monday but it is becoming “more and more difficult” to save the accord, she said.

“We might have a Joint Commission meeting in the coming days,” Mogherini said, referring to the forum where the signatories can discuss problems and potentially set the ground for exploring sanctions.

A senior EU diplomat said the Joint Commission meeting in Vienna could be next week at the level of political directors.

Any of the signatories can trigger a dispute resolution process that could culminate at the U.N. Security Council with a so-called “snapback” of global, U.N. sanctions on Iran.

The EU countries want the International Atomic Energy Agency must first verify Iran’s latest announcements on enrichment, EU diplomats said.

Iran says it wants nuclear energy only for civilian applications.

Under President Donald Trump, the United States has said the curbs imposed on Iran were not rigorous enough, and did not address its ballistic missile programme.