Georgian and U.S. troops started a joint military exercise Tuesday amid growing tensions between the ex-Soviet republic and Russia, a Georgian defense ministry official said.

About 1,200 U.S. servicemen and 800 Georgians will train for three weeks at the Vaziani military base near the Georgian capital, Tbilisi, ministry spokesman Mindiya Arabuli said. He said the drills were planned months ago and are not related to recent tensions over two separatist Georgian regions that are backed by Moscow.

Georgian President Mikhail Saakashvili has courted the United States and sent a large contingent of troops to Iraq. His efforts to move Georgia from under Russia's shadow and into NATO have angered Moscow, which has stepped up support for the breakaway regions of Abkhazia and South Ossetia.

Also Tuesday, the Russian Defense Ministry started a military exercise in the nearby North Caucasus region. Ministry spokesman Yuri Ivanov said the drill had "nothing to do" with the Georgian-U.S. maneuvers.

Georgia claims a string of recent explosions and border skirmishes in Abkhazia and South Ossetia are part of a Russian plan to annex the regions, while Russia claims Georgia is gearing up for a mid to take control of the regions by force.