Merkel, who visited Tbilisi for talks with Georgian President Mikheil Saakashvili on Sunday, said support for Georgia's bid to join NATO was laid out in documents produced at the military alliance's summit in Bucharest in April.
"They contain, which is rather unusual, a very firm pledge that both Ukraine and Georgia will become NATO members," Merkel said. "The first review of the situation will take place in December."
NATO declined at the Bucharest summit to grant both Georgia and Ukraine a Membership Action Plan (MAP) which would have set the two former Soviet republics on the road to membership of the 26-nation military alliance. Germany and France expressed concern that doing so would unnecessarily antagonize Russia. Georgia's "frozen" conflicts in South Ossetia and Abkhazia, another Georgian breakaway republic, were also cited. The countries had received strong U.S. backing for their bids.
Commenting on the recent conflict in Georgia, Merkel said it was a priority for Russian troops to pull out from the South Caucasus state as soon as possible.
"I expect the quick withdrawal of Russian troops, which, according to information at my disposal, has not so far been conducted the way we expected," Merkel said.
Russian President Dmitry Medvedev said on Sunday during a telephone conversation with his French counterpart Nicolas Sarkozy that Russian troops would start their pullout from Georgia on August 18. Medvedev signed on Saturday a French-brokered plan on resolving the conflict in Georgia.
Georgia launched a major ground and air offensive to seize control of South Ossetia on August 8, prompting Russia to send in tanks and thousands of troops. Russia concluded its operation to "force Georgia to accept peace" on August 12.
At a meeting in the Black Sea resort of Sochi with Medvedev last Friday, Merkel called Russia's reaction "disproportionate." Her words echoed criticism of Moscow's response to the Georgian attack by U.S. President George Bush.
NATO foreign ministers will consider rendering military reconstruction aid to Georgia at a meeting on Tuesday, the German chancellor said. She also promised Saakashvili assistance in restoring Georgian infrastructure.
NATO refused last Tuesday to rule out the prospect of Georgia joining the military alliance in the future.
"I think that the Bucharest communique stands. The allies have said in Bucharest that one day Georgia will join NATO," Secretary-General Jaap de Hoop Scheffer told a news conference following NATO talks with Georgia in Brussels.