“In central Europe, clearly we [NATO and Russia] have two different visions of what European security should be like," Vershbow said Thursday.

“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,” Alexander Vershbow said as quoted by US media.

NEW YORK, May 02, /ITAR-TASS/. NATO will have to treat Russia more as an adversary rather than a partner, a deputy secretary-general of the North Atlantic alliance said.

He stressed that the alliance “still would defend the sovereignty and freedom of choice of Russia's neighbors” and accused Moscow of “trying to re-impose hegemony and limit their [neighboring states’] sovereignty under the guise of a defense of the Russian world.”

Vershbow told reporters that the events in Ukraine, including Crimea’s incorporation by Russia, were the reason why the relations between NATO and Russia deteriorated.

NATO suspended “practical civilian and military cooperation” with Moscow last month.

Vershbow said the alliance is considering deployment of additional forces in Eastern Europe permanently or on a rotation basis, in particular, to strengthen the security of the Baltic states.

“We want to be sure that we can come to the aid of these countries if there were any, even indirect, threat,” he said.

Earlier this week, four Danish F-16 jets landed at the Estonian airbase Amari. The Danish contingent will as part of a NATO mission patrol the Baltic states’ airspace for four months. The second part of that mission is carried out by a Polish-British contingent from the Zokniai (Siauliai) airbase in Lithuania.

Ukraine is in turmoil after a coup took place in the country in February, with new people brought to power amid deadly riots as security concerns prompted President Viktor Yanukovich to leave Ukraine.

The Republic of Crimea and Sevastopol, a city with a special status on the Crimean Peninsula, where most residents are Russians, struck agreements to reunify with Russia on March 18 after a referendum two days earlier in which an overwhelming majority of Crimeans voted to secede from Ukraine and join the Russian Federation.

Kiev and Western nations do not recognize Crimea’s reunification with Russia despite Moscow's repeated statements that the Crimean plebiscite conformed to the international law and the UN Charter and was in line with the precedent set by Kosovo’s secession from Serbia in 2008.

After Crimea's accession to Russia, protests against the new Ukrainian authorities erupted in Ukraine’s Russian-speaking southeastern regions, with demonstrators, who are demanding referendums on the country’s federalization, seizing some government buildings.

Ukrainian parliament-appointed interim head of state Alexander Turchinov on April 15 announced the start of an antiterrorism operation in the Donetsk Region in eastern Ukraine. Moscow has condemned the operation, which is apparently aimed to crack down on federalization supporters.

Russian President Vladimir Putin on Tuesday dismissed Western claims that Russia could be involved in pro-federalization protests in southeastern Ukraine.

“People say our special forces are present there [in Ukraine], say we have sent instructors there. Let me say in all responsibility that there are no Russian instructors, special forces or troops of any kind there. We have no one there,” Putin said in the Belarusian capital Minsk, where he went for integration talks with the leaders of Belarus and Kazakhstan.