The three European powers party to the deal act though the EU, which coordinates any negotiations over it with the other parties, which include Russia and China
France, Britain and Germany plan to trigger on Tuesday the dispute mechanism in the Iran nuclear deal following renewed violations by Tehran of the 2015 accord, two European diplomats said on Tuesday.
The diplomats said the decision was aimed at saving the deal by discussing with Iran what it should do to reverse decisions it had made. The aim was not to reimpose UN sanctions, they said.
The three powers will inform the European Union on Tuesday they plan to trigger the mechanism, the sources said. EU foreign policy chief Josep Borrell is expected to make a statement in Strasbourg at the European Parliament at midday.
Iran took a further step back from its commitments to the 2015 pact, with six world powers, by announcing earlier this month that it would scrap limits on enriching uranium, though it said it would continue to cooperate with the U.N. nuclear watchdog.
"At one point we have to show our credibility," said one diplomat referring to Iran's recent nuclear decisions.
The three European powers party to the deal act though the EU, which coordinates any negotiations over it with the other parties, which include Russia and China.
"Our intention is not to restore sanctions, but to resolve our differences through the very mechanism that was created in the deal," a second diplomat said.