The war in Ukraine should end a cycle of Russian aggression that goes back much further than the invasion launched by Moscow a year ago, NATO Secretary General Jens Stoltenberg told Reuters.

In an interview with the agency on the eve of the first anniversary of Moscow's attack, Stoltenberg said the invasion was part of a pattern that included Russian military action in Georgia in 2008 and in Ukraine's Crimea in 2014.

Stoltenberg said no one knows when the war will end, but they do know that when it does, they need to do everything to make sure history doesn't repeat itself.

NATO needs to break the cycle of Russian aggression. They need to prevent Russia from undermining European security, he told Reuters at NATO headquarters on the outskirts of Brussels.

He explained that this means that Ukraine must have the military capacity, the strength, to deter further aggression.