PODGORICA - Montenegro officials on Wednesday welcomed the U.S. Senate's decision to ratify its entry into NATO, calling it a great step for the tiny Balkan nation.



Montenegro is set to become NATO's 29th member following the Senate's overwhelming ratification on Tuesday.



Russia, though, strongly opposes the Western military alliance's expansion in the Balkans. Russia has been accused by Montenegro of trying to stage an election day coup in October to try to keep the country out of the alliance.



Montenegro Prime Minister Dusko Markovic said that Montenegro never doubted U.S. support for the country.



He said Montenegro's membership in NATO will be its biggest foreign policy success since it gained independence and split from much-bigger Serbia in a 2006 referendum.



Russia considers Montenegro and other western Balkan states part of its sphere of interest. Wary of Russian influence in the still-volatile region, NATO wants Montenegro to join the alliance.



The pro-Russian opposition parties in Montenegro reacted by saying they are demanding a referendum on NATO entry.



The NOVA party said in a statement that the membership would represent “a brutal occupation” of Montenegro, adding that the alliance's soldiers would be treated as “occupiers.”



U.S. Senators voted 97-2 on Tuesday to admit Montenegro, with only Republican Senators Rand Paul of Kentucky and Mike Lee of Utah voting “no.” Paul had suggested that adding Montenegro could lead to heightened tension with Moscow, possibly even war.



Under NATO's principle of collective defense, an attack against one ally is considered an attack against them all.



Despite its size, Montenegro bears strategic importance. A former ally of Russia, the country is in the middle of a clash between the West and Moscow over influence in the Balkans. Montenegro's membership gives NATO a contiguous border along the Adriatic coast.