MOSCOW, August 11 (RIA Novosti) - Georgia's breakaway republic of Abkhazia told Georgia on Monday that if its troops fail to leave the strategic Kodori Gorge, separatist forces will begin a full-scale onslaught to force them out.

Abkhazia's pro-Russian leadership pledged on Sunday to oust Georgian forces from the northern part of the gorge, the only part of the province still controlled by Georgia, two days after Georgia began a ground and air offensive in its other separatist republic, South Ossetia.

"We will begin an operation to force out all Georgia's security forces located there. This will be a combat operation with the employment of all our military's armaments," Abkhaz President Sergei Bagapsh said in an interview with the Russian TV channel Vesti.

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 tanks and hundreds of troops, and striking military targets across Georgia.

Around 2,000 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 on Sunday martial law 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 assault on Abkhazia.