"Clearly the Russians have declared NATO as an adversary, so we have to begin to view Russia no longer as a partner but as more of an adversary than a partner," said Alexander Vershbow, the deputy secretary-general of NATO.
In a question-and-answer session with a small group of reporters, Vershbow said Russia's annexation of Crimea and its apparent manipulation of unrest in eastern Ukraine have fundamentally changed the NATO-Russia relationship.
In April, NATO suspended all "practical civilian and military cooperation" with Russia, although Russia has maintained its diplomatic mission to NATO, which was established in 1998.
Vershbow said NATO, created 65 years ago as a bulwark against the former Soviet Union, is considering new defensive measures aimed at deterring Russia from any aggression against NATO members along its border, such as the Baltic states that were once part of the Soviet Union, Vershbow said.
To do that, NATO members will have to shorten the response time of its forces, he said.
Vershbow, a former US ambassador to NATO, said that among possible moves by NATO is deployment of more substantial numbers of allied combat forces to Eastern Europe, either permanently or on a rotational basis.
