NATO Secretary-General Anders Fogh Rasmussen on August 7 vowed support for Ukraine in the face of Russian "aggression" and called on Moscow to pull back its troops from the border.
Rasmussen, speaking on a visit to Kyiv, called on Russia "to step back from the brink, step back from the border and not use peacekeeping as an excuse for war-making."
He said that Russia, instead of deescalating the conflict, continues to destabilize Ukraine, and that its support for pro-Russian separatists fighting government forces in the east grows "in scale and sophistication."
Rasmussen also noted that NATO suspends cooperation with Russia.
"The Alliance condemns the actions of the Russian Federation, which led to the violation of the territorial integrity of Ukraine and annexation of Crimea ... Currently, the North Atlantic Alliance is suspending cooperation with the Russian Federation, strengthening collective defense for the protection of all NATO members.
NATO said on August 6 that a Russian forces buildup near the Ukrainian border amounts to some 20,000 troops.
The alliance said Moscow could use the excuse of a humanitarian or peacekeeping mission to send them into Ukraine.