Islamic state vows to keep up violations of nuclear deal until it is confident Washington's countermeasures will end

Iranian source tells state media country formally notified Britain, France, and Germany it is willing to meet with reps on their turf or in Tehran, but so far has had no response

Bloc says its diplomatic service is 'sparing no efforts' to restart Vienna negotiations with all parties to 2015 nuclear pact

Ali Bagheri said meeting with EU's Enrique Mora would include discussion of lifting 'cruel sanctions' imposed after US pulled out of 2015 pact