Kremlin spokesman Dmitry Peskov said the probability of military conflict in eastern Ukraine being initiated by the Ukrainian side was higher than ever.
Peskov added that Ukraine has deployed a large number of troops near the borders of breakaway regions controlled by pro-Russian separatists which he said indicated that Kyiv was preparing to attack them. Ukraine has repeatedly denied this.
Peskov said information coming from the West was filled with "hysteria" and "laced with lies".
NATO said earlier it was putting forces on standby and reinforcing eastern Europe with more ships and fighter jets in response to Russia's military build-up at Ukraine's borders.
The move added to a flurry of signals that the West is bracing for an aggressive Russian move against Ukraine, though Moscow denies any plan to invade.