NATO Secretary General Jens Stoltenberg sees a great potential for closer cooperation between the European Union and NATO in hybrid warfare and how they defend all the allies against hybrid warfare.

"Hybrid warfare is the combination of military and non-military means, it's about… covert operations, it's about deception, it's about using economic tools, communications, disinformation and we have already had a comprehensive and broad response to hybrid warfare," he said in Brussels on Monday at the pre-ministerial press conference.

The NATO Foreign Ministers will meet in Antalya, Turkey, on May 13 and May 14.

"NATO has, of course, unique capabilities, capacity and experience, but we also need… other means to be able to protect our allies against hybrid warfare related to economic measures, energy, cyber and so on. So this is an area where there is a great potential for the European Union and NATO working together," he said.