France, Germany and the United Kingdom on Thursday formally notified the UN Security Council that they are activating the “snapback” clause of Resolution 2231, starting a 30-day procedure that will restore all United Nations sanctions lifted under the 2015 Iran nuclear agreement. In the letter seen by Reuters, the three governments—collectively known as the E3—argue that Iran remains in “significant non-performance” of its commitments, citing continued uranium enrichment of up to 60 % purity. Unless the Council adopts a resolution to maintain the current sanctions relief within 30 days, restrictions on Iran’s financial, hydrocarbons, defence and shipping sectors will automatically return. The European powers said the step was necessary before their authority to invoke snapback expires in mid-October, but stressed they remain open to negotiations during the 30-day window. They indicated the process could be halted if Tehran allows full International Atomic Energy Agency inspections and offers verifiable assurances about its nuclear programme. Iranian Foreign Minister Abbas Araghchi condemned the move as “illegal and unjustified” and warned of a proportionate response, while suggesting it would damage cooperation with the IAEA. U.S. Secretary of State Marco Rubio welcomed the notification and pledged support for re-imposing the measures unless a new agreement is reached. Diplomats said the Security Council will meet on Friday to discuss the E3 request.