Weapons leaning together as soldiers stand in formation during a military exercise at Vaziani military base Tuesday.
Officials said the exercise, called "Immediate Response 2008," had been planned for months and was not linked to a standoff between Moscow and Tbilisi over the breakaway Georgian republics of Abkhazia and South Ossetia.
"The main purpose of these exercises is to increase the cooperation and partnership between U.S. and Georgian forces," Brigadier General William B. Garrett, commander of the U.S. military's Southern European Task Force, told reporters.
The war games involve 600 Georgian troops and smaller numbers from the former Soviet republics of Armenia, Azerbaijan and Ukraine.
The two-week exercise was taking place at the Vaziani military base, near Tbilisi, which was a Russian Air Force base until Russian forces withdrew at the start of this decade under a European arms-reduction agreement.
Georgia and the Pentagon cooperate closely. Georgia has a 2,000-strong contingent supporting the U.S.-led coalition in Iraq, and Washington provides training and equipment to the Georgian military.
Georgia last week recalled its ambassador in Moscow in protest to Russia sending fighter jets into Georgian airspace. Tbilisi urged the West to condemn Russia's actions.
Russia said the flights were to prevent Georgian President Mikheil Saakashvili from launching a military operation against South Ossetia.
It was Russia's first admission for at least a decade that its air force had flown over Georgian territory without permission. Georgia has said in the past that Russia trespassed in its airspace, but Moscow has always denied it.
NATO said Tuesday that it was troubled by the Russian overflights, saying they called into question Moscow's role as a peacekeeper and facilitator of talks between Tbilisi and separatists.
NATO Secretary-General Jaap de Hoop Scheffer urged all parties, including Russia, to support Georgian territorial integrity as called for in UN Security Council resolutions, alliance spokesman James Appathurai said.
"The secretary-general is concerned by the recent escalation of tension in Georgia, he is troubled by Russia's statement that its military aircraft deliberately overflew Georgian territory in violation of its territorial integrity," Appathurai said.
"These actions raise questions about Russia's role as peacekeeper and facilitator of negotiations," he said, speaking on behalf of de Hoop Scheffer.
Early this year, Russia established semiofficial ties with South Ossetia, and Abkhazia and beefed up the peacekeeping forces it has had in Abkhazia since the end of a war in the 1990s.
Georgia accused Russia of trying to annex its territory, and Tbilisi's Western allies said Russia was stoking tensions. Russia, angered by Georgia's hopes to join NATO and the European Union, said it acted to defend the breakaway regions from Georgian aggression.
The United States on Monday criticized Russia as well for intentionally violating Georgian airspace.
U.S. State Department spokesman Sean McCormack said, "We are deeply troubled by Russia's statement that its military aircraft deliberately violated Georgia's internationally recognized borders."
In a statement issued late Monday, McCormack urged all countries, "including Russia," to "support Georgia's sovereignty and territorial integrity within its internationally recognized borders."