Russia's recent behaviour is more aggressive but does not pose an immediate threat to NATO, the alliance's chief Jens Stoltenberg said on Thursday.
"We do not see an immediate threat from the East against any NATO country," Stoltenberg told Norwegian radio NRK, when asked whether Russian President Vladimir Putin was a threat to peace.
"What we see is increased unpredictability, increased insecurity, increased nervousness," the former Norwegian prime minister said during his first official visit to his native country since taking over as NATO secretary general last year.
Stoltenberg painted a picture of a heavily re-militarised Russia "which is unfortunately now more aggressive than it was a few years ago," and which doesn't hesitate "to resort to military force to re-draw the borders in Europe," citing Crimea, Ukraine and Georgia as examples.
Like Ukrainian authorities, Western countries accuse Russia -- which annexed the Crimean peninsula in early 2014 -- of arming the rebellion in eastern Ukraine and of having sending regular troops there, which Moscow fiercely denies.
"Our aim is to cooperate with Russia," Stoltenberg said.
"That benefits NATO, that benefits Russia," he added.
Despite an official ceasefire, at least 24 people, most of them separatists, have been killed in renewed fighting between government forces and pro-Russian rebels in the past 24 hours in Ukraine's east, according to Ukrainian authorities and the separatists.