His virtual address is regarded as the keynote speech for a June 14 NATO in-person summit involving world leaders, including U.S. President Joe Biden.

Speaking in Brussels, Stoltenberg spoke of adherence to the NATO 2030 agenda, a policy statement issued in 2020 calling for "making sure [that] NATO remains strong militarily, becomes even stronger politically and takes a more global approach."

Earlier this week, he recommended that the 30-nation military bloc engage in more effective pooling of resources.

"In a more competitive and unpredictable world, we need transatlantic unity -- Europe and North America standing strong together in NATO -- so the goal of our NATO 2030 initiative is to prepare our alliance for the future," Stoltenberg said.

In the keynote speech on Friday, he outlined key agenda points for the summit, notably a strengthening NATO as a forum for political consultations, reinforcing collective defense through improved readiness, modernized capabilities and objectives to make societies less vulnerable to attack and coercion.

"To do all of this we need to invest more," Stoltenberg said, mentioning seven years of consecutive defense spending increases by Canada and European allies. "We should also invest better. That is why we should increase NATO's common-funded budget."

Stoltenberg also met with Lithuanian Prime Minister Ingrida Simonyte on Friday, and afterward denied that Turkey, a NATO member, persuaded the bloc to soften its stance in condemning Belarus for its forced diversion of a plane traveling from Athens to Vilnius, Lithuania, on May 23.

"NATO is united and NATO allies, all 30 NATO allies, agreed a very strong statement last week, where we strongly condemned the forced landing of civilian aircraft on its way from one NATO capital Athens to another NATO capital Vilnius," Stoltenberg said.

The European Union and the United State have also condemned the incident.

Simontye called the NATO statement "strong and timely."