EU leaders meeting in Brussels welcomed High Representative Federica Mogherini's report on progress made in the field of defence cooperation and rapidly and unanimously agreed on a further major boost by activating Treaty provisions for Permanent Structured Cooperation. "This is one of the fields where the European Union project can be re-launched," Mogherini said ahead of the meeting, adding that the endorsement of the Heads of State and Government would "give further impulse so that Foreign and Defence Ministers together with me can follow up in the coming months and come back in December with even more decisions taken."

European Council President Donald Tusk said the agreement was "a historic step, because such cooperation will allow the EU to move towards deeper integration in defence. Our aim is for it to be ambitious and inclusive, so every EU country is invited to join. Within three months, Member States will agree a common list of criteria and commitments, together with concrete capability projects, in order to take this cooperation off the ground.