Finnish President Alexander Stubb told CNBC Tuesday that Ukraine has already won the war against Russia — even as he warned that Kyiv still urgently needs more air defense support from NATO allies.

Stubb highlighted that Ukraine had managed to preserve its independence, sovereignty and territorial integrity despite more than four years of full-scale invasion by Moscow.

"Look at things from a Moscow perspective: In the past four years, during the active war, they have advanced 60 kilometers. In World War II, they went from Moscow to Berlin, that's 1,400 kilometers. You have to ask yourself: 'Who has won, who has lost?' I say Ukraine has won," Stubb said at the NATO Summit in Ankara, Turkey on Tuesday.

"My message is that yes, Europe needs to ramp up, but you know what, Ukraine needs NATO, but NATO needs Ukraine as much as the other way around," he added.

Sweden's Prime Minister Ulf Kristersson struck a similar tone earlier in the day.

"Russia is certainly not winning the war against Ukraine right now, that's quite obvious, Ukraine is having spectacular successes," Kristersson said. "Russia is not at all managing this war as they anticipated in the beginning."

The Nordic leaders' comments come as NATO allies gather in the Turkish capital for a summit dominated by Ukraine's future, Russia's threat to Europe, and the scale and speed at which European countries can reduce their reliance on the U.S.

It marks one year since NATO leaders committed to hiking defense spending from 2% to 5% of GDP by 2035, following years of pressure from Washington and after Russia invaded Ukraine.

Stubb called last year's agreement "historic" and said the Ankara summit would be judged by whether allies could show they were implementing it.

"That's why we're talking about NATO 3.0. That's why we're talking about burden shifting from the United States to Europe, and that's why we're basically talking about a stronger Europe in a stronger NATO," he said.

The Finnish president, who leads a country that shares a 1,340-kilometer border with Russia, said European allies had heard Washington's message on defense spending and military readiness.

"The Americans, we have heard them loud and clear: take more responsibility of your own defense. That means in war time, so crisis time, in peacetime, and in planning, and that's exactly what we're doing," Stubb said.

But Ukraine still needs substantial military support, particularly in air defense, he added.

"We shouldn't be all smiles about it, because Zelenskyy needs air defense, and that's where we need to help Ukraine as much as possible."

Sweden's Kristersson said that the question now was "on whose side is time," arguing that Russia was betting on Europe becoming tired, distracted or intimidated by the war and its costs.

"Time is not on Russia's side right now, unless we allow it to be," he said. "Russia is hoping for Europe to get tired of this war, to say that we have other priorities, or to be scared, and right now I think we are proving the opposite."

The Swedish leader pointed to Europe's 90 billion euro ($103 billion) loan package as an example of staying united behind Ukraine.

He said that Sweden was moving ahead with plans to provide Ukraine with Saab-made Gripen fighter jets, including newer-generation aircraft for purchase and older models as support.

"This is a very good start that will increase, enhance the Ukrainian defense capability," Kristersson said.

Kristersson's and Stubb's comments reflect a broader shift among NATO allies since Russia's invasion of Ukraine. Finland joined the alliance in 2023. Sweden followed in 2024, ending two centuries of military non-alignment.

Both countries now argue their defense buildup is being driven less by U.S. pressure than by Russian aggression.

"We do what we are doing not because of American rhetoric but because of Russian behavior. That needs to be very clear," Kristersson said. "Russia is the defining threat to our part of the world, and that is why we are doing what we are doing." 

Still, the NATO summit has been overshadowed by questions about whether the U.S. will reduce its military footprint in Europe faster than allies can build up their own defense-industrial base.

Kristersson said he accepted the U.S. argument that Europe needed to do more, noting that multiple American administrations had made that point for decades.

"That is not an unreasonable demand, and now things are happening," he said. "You could say that it would have been better if Europe had reacted earlier, if we didn't downsize our defense capabilities in such a severe way as we did, including Sweden, honestly. But now we are back on track."

But he also warned that the shift from U.S. to European responsibility had to be managed carefully.

"We agree with the fact that there should be a burden shift, and the more orderly we can do that, the more open we can be, the more transparent we can be towards each other, the more successful will this burden shift become."