BRUSSELS - NATO and the European Union (EU) leaders plan to sign a new joint declaration in July to further enhance their level of cooperation, NATO Secretary General Jens Stoltenberg announced Friday.

Joined by the EU foreign policy chief Federica Mogherini and defense ministers from Finland and Sweden, NATO defense ministers met Friday to review the progress in NATO-EU cooperation.

Speaking at a press conference, Stoltenberg said the two organizations have been working together on 74 concrete areas of cooperation, including hybrid and cyber, maritime operations, exercises and military mobility, and the fight against terrorism.

"We discussed how NATO and the EU could cooperate even more closely going forward," Stoltenberg said, adding that "military mobility is one area that will become a flagship in our cooperation."

He welcomed the EU's efforts on defense, and stressed that NATO-EU cooperation and the EU's steps can complement each other.