STORY: "When the war (between Russia and Ukraine) ends, ... we must ensure that when it does, we have credible arrangements in place to guarantee Ukraine security in the future and to break Russia's cycle of aggression", Stoltenberg said following an informal meeting of NATO countries' foreign ministers in Oslo.

"The details (on) how this will be done, what kind of mechanisms: that remains to be decided, but the idea of preventing history from repeating itself, preventing (Russian) President (Vladimir) Putin from continuing to be able to chip away at European security: that's the aim."