Brussels  - The head of NATO is "seriously concerned" by the outbreak of fighting in Georgia and calls on all sides to return to the negotiating table, a statement released in Brussels said Friday.

NATO Secretary General Jaap de Hoop Scheffer is "seriously concerned about the events that are taking place in the Georgian region of South Ossetia," and said that NATO is "closely following" the situation, the statement said.

De Hoop Scheffer "calls on all sides for an immediate end of the armed clashes and direct talks between the parties," it said.

South Ossetia fought a war of independence against Georgia in the early 1990s. Since 1994 it has exercised de facto independence which has not been recognized internationally, and has been occupied by Russian peacekeepers.

In recent years Georgia has attempted to move closer to NATO, being promised eventual membership by alliance leaders in April. Russia, which views the proposal as a threat to its security, warned that such a move could destabilize the Caucasus region.

Since the April promise, tensions between Georgia and its breakaway regions have flared, with Moscow and Tbilisi each accusing the other of stoking the conflict.

Fighting broke out between Georgian troops and South Ossetian forces on Saturday and has intensified throughout the week. (dpa)