Russia is suffering "crazy losses" in Ukraine, tallying around 65,000 soldiers over the last two months, NATO Secretary General Mark Rutte said on Saturday at the Munich Security Conference.

Separately, he told a media roundtable that the NATO alliance was strong enough that Russia would not currently try to attack it.

"We will win every fight with Russia if they attack us now, and we have to make sure in two, four, six years that same is still the case," he said.