"It has been a year since my first visit to NATO headquarters," Kaljulaid said according to an Office of the President press release. "I am glad to see that NATO has successfully adapted to the new security situation. The increased presence of NATO allies has bee very successful, and it is important continue strengthening deterrence and defense, she added.

According to Kaljulaid, the alliance must also address challenges originating from the south, and confirmed that Estonia is seeking opportunities for contributing with its own expert to the so-called "southern center" in Naples.

"Cooperation between NATO and the EU has reached a new level in the past year," the Estonian president noted. "I am glad about the parallel training and cooperation in the cyber field. In addition to deepening existing areas of cooperation, I see military mobility as a new topic." Developments in Europe's defense field do not compete with NATO, but rather offer new opportunities for cooperation, she added.

Other topics discussed at Thursday's meeting included the NATO summit to be held in Brussels next year, partnership relations with Ukraine and Georgia as well as reations with Russia.

Kaljulaid returned to Estonia following a three-day visit to Belgium on Thursday night.