BRUSSELS - Negotiations to end the fighting in South Ossetia must be based on Georgia's territorial integrity, NATO said Saturday, as it renewed its call for direct talks between the warring sides.

"NATO remains very concerned, there is no doubt about that," said a spokeswoman at the Brussels headquarters of the North Atlantic Treaty Organization, which Georgia is keen to join despite Russian objections.

"The negotiations that we, NATO, and others are calling for can only be based on Georgia's territorial integrity," she told AFP, adding that NATO officials remain in contact with counterparts in both Georgia and Russia.

NATO staked out its position as Russian Prime Minister Vladimir Putin said there was little chance of separatist South Ossetia reintegrating with the rest of Georgia after this week's fighting.

The NATO spokeswoman said: "The NATO secretary general (Jaap de Hoop Scheffer) continues to believe that all sides involved must immediately cease military operations and start negotiating."

Georgia, a republic in the erstwhile Soviet Union, is keen to join NATO, after a summit of the transatlantic alliance in Bucharest in April declare -- without setting a date -- that it will become a member.

Russia objects to such a move, which is championed by the United States and which political analysts say would erode Moscow's influence in the strategic Caucasus region.

On Friday, Scheffer was one of the first to call for an end to the fighting in South Ossetia, and swiftly embarked on a blitz of telephone diplomacy.

He talked at least twice with Georgian President Mikheil Saakashvili, as well as with Russian officials, urging them to cease hostilities.

Sheffer has not yet, however, made contact with either Russian President Dmitry Medvedev or Prime Minister Vladimir Putin, the spokeswoman said.

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