French President Francois Hollande said Friday Russia should not be considered a threat but rather a partner, as NATO leaders met to endorse a revamp to counter a more aggressive Moscow.

"NATO has no role at all to be saying what Europe's relations with Russia should be. For France, Russia is not an adversary, not a threat," Hollande said as he arrived for a landmark alliance summit in Warsaw.

"Russia is a partner which, it is true, may sometimes, and we have seen that in Ukraine, use force which we have condemned when it annexed Crimea," he added.

The NATO summit is finalising the biggest military build-up since the end of the Cold War in response to Russia's shock 2014 Ukraine intervention and annexation of Crimea.

France and several other NATO allies such as Germany and Italy have pressed for the alliance to keep its lines of communication with Moscow open so as to avoid getting stuck in a Cold War-style stand-off.

Hollande has also played a key role, along with German Chancellor Angela Merkel, in efforts to implement the Minsk ceasefire accords agreed with Russia and Ukraine but which continue to be breached on a daily basis.

"We are still trying, and again recently with Madame Merkel, to find a solution to the Ukraine crisis," the French president said.

He said France believed it was important to bolster NATO so it could carry out its mission but all had to do their bit.

"France will do what it has to do but no more," he added.