A diplomat says that representatives of three European countries threatening to reimpose U.N. sanctions on Iran over its nuclear program failed to agree with their Iranian counterpart on how to avoid the move,

Britain, France and Germany plan to jointly notify the U.N. Security Council that Iran is in “significant” violation of the 2015 nuclear deal.

Britain, France and Germany are likely to begin the process of reimposing U.N. sanctions on Iran on Thursday, but hope Tehran will provide commitments over its nuclear programme within 30 days that will convince them to defer concrete action,