Medvedev's predecessor Vladimir Putin, who is now Russia's powerful prime minister, often accused the West in the past of trying to expand its clout in the ex-Soviet nations and push Russia out of its traditional sphere of influence. The Kremlin has fiercely opposed NATO's plans to incorporate its ex-Soviet neighbors, Ukraine and Georgia.

Russia currently controls most natural gas export routes out of the former Soviet region, but that grip is coming under growing pressure from China and the West.

Intensifying rivalry for influence in the ex-Soviet region fomented tensions and helped stage the ground for last August's war between Russia and Georgia, which sits astride a key export pipeline carrying Caspian oil to Western markets.

The war erupted when the U.S.-allied Georgian President Mikhail Saakashvili sent troops to regain control over the separatist province of South Ossetia, which had close links with Russia.