Russia and Georgia's breakaway region of South Ossetia have signed a "border agreement" opposed by Tbilisi.
Russian Foreign Minister Sergei Lavrov and the de facto foreign minister of South Ossetia's separatist government, David Sanakoyev, signed the document in Moscow on February 18.
In November, Moscow signed an "alliance and strategic partnership" treaty with Georgia's another breakaway region, Abkhazia.
Georgia has opposed the deals, saying they would increase Russia's presence in South Ossetia and Abkhazia.
Last month, Georgian Foreign Minister Tamar Beruchashvili said Moscow could annex South Ossetia as it did Ukraine's Crimean Peninsula.
Also last month, Georgian Prime Minister Irakli Garibashvili urged the European Union to strongly oppose the border deal between Russia and South Ossetia.
Russia recognized South Ossetia and Abkhazia as independent nations after fighting a five-day war with Georgia in 2008.
Based on reporting by TASS and Interfax