The West has criticized an agreement between Russia and Georgia's breakaway region of Abkhazia.
Russian President Vladimir Putin and the leader of Abkhazia signed the "strategic partnership" deal on November 24 in the Black Sea resort of Sochi, just across the border from the separatist region.
Tbilisi condemned the pact as an attempt by Moscow to annex the region.
Under the document, Russian and Abkhaz forces in the territory will turn into a joint force led by a Russian commander.
Putin said Moscow will also double its subsidies to Abkhazia to about $200 million next year.
In Washington, the State Department said it would not recognize any "so-called treaty" between Russia and Abkhazia.
NATO Secretary-General Jens Stoltenberg said the accord would not help achieve a peaceful settlement to the situation in Georgia.
EU foreign policy chief Federica Mogherini said the agreement violated Georgia's sovereignty and territorial integrity.
Moscow recognized Abkhazia and another Georgian breakaway territory, South Ossetia, as indepedent states in 2008.
That move came after Russia and Georgia fought a brief war over South Ossetia.
Abkhazia broke away from Georgia during a brutal war in the early 1990s, during which much of the region's ethnic Georgian population fled.
Georgian Foreign Minister Tamar Beruchashvili denounced the new agreement as a "step towards annexation of Abkhazia by the Russian Federation."
Georgian President Georgy Margvelashvili called the agreement "absurd and illogical."
The deal comes amid tense ties between the West and Moscow over Ukraine, raising questions over Moscow's future plans.
The Black Sea region has always been important to Putin, who justified the annexation of Crimea in March by saying it would guarantee that NATO warships would never be welcome on the peninsula, home to the Russian Black Sea Fleet.
Abkhazia's former leader, Alexander Ankvab, was forced to step down earlier this year following protests, allegedly encouraged by the Kremlin.
The present leader, Raul Khajimba, is a former KGB officer and was elected president in an early poll in August.
Unlike Ankvab, who resisted Moscow pressure to let Russians buy assets in Abkhazai, Khajimba has appeared more willing to listen to Russia's demands.
Some Georgian officials fear Putin may now sign a similar deal with South Ossetia, which already depends on Moscow for financial and political support.
With reporting by AP and Reuters