Speaking at a press conference in Tbilisi alongside Georgia's Prime Minister Irakli Garibashvili, Stoltenberg reiterated NATO's promise to accept Tbilisi as a full ally once it meets membership criteria.

"NATO stands by your side as you continue your path towards stronger democracy and full Euro-Atlantic integration, including the 2008 Bucharest decision that Georgia will become a member of NATO alliance," he said.

At a 2008 summit in the Romanian capital Bucharest, NATO leaders granted Georgia an integration perspective, without putting it on a formal membership path.

"It is important that Georgia continues to strengthen domestic reforms, democratic values, and the rule of law, including through free and fair parliamentary elections in October this year," Stoltenberg added.

Georgian government has faced a growing international criticism over perceived backsliding on democracy.

Stoltenberg also said that "Georgia is facing complex security challenges" in the face of Russia's "imperial ambitions."

Membership in NATO and the European Union is enshrined in the country's constitution and supported -- according to opinion polls -- by some 80 percent of population.

The bid has angered Georgia's Soviet-era master Moscow.