"The armed forces of Abkhazia have reached the border with Georgia in the Kodori Gorge," General Anatoly Zaitsev said.
Georgia's breakaway republic of Abkhazia started early Tuesday a full-scale onslaught to force Georgia's troops from the northern part of the gorge, the only part of the province still controlled by Georgia.
The move came a day after Abkhazia issued an ultimatum to Georgia to leave the strategic region, three days after Tbilisi began a ground and air offensive in its other separatist republic, South Ossetia.
Abkhaz President Sergei Bagapsh told a Security Council session in Sukhumi the operation in the Kodori Gorge, located in the breakaway republic and which Georgia occupied in 2006 in violation of a 1994 ceasefire agreement, would continue until the "jurisdiction" of Abkhazia was restored.
Georgia now faces the prospect of permanently losing all control over both its breakaway regions, following its costly attempt at seizing South Ossetia. Russia, which supports both regions and has given Russian citizenship to most of their residents, retaliated to the Georgian offensive by sending in hundreds of tanks and thousands of troops, and striking military targets across Georgia.
Around 1,600 people in South Ossetian capital, Tskhinvali, were killed by Georgian forces, according to Russia, and at least 34,000 locals fled north across the Russian border.
Abkhazia, which has an agreement with South Ossetia on military assistance in the event of armed conflicts, imposed martial law on Sunday in the areas bordering Georgia, and announced partial mobilization.
Russia has committed more than 9,000 paratroopers and 350 armored vehicles to Abkhazia in an attempt to prevent the South Ossetian conflict spreading, and to guard against a potential Georgian attack on Abkhazia.
