Georgia's attack on South Ossetia was likely approved by the United States, says Russian Ambassador to the UN, Vitaly Churkin.

"It is hard to imagine that (Georgian President Mikheil) Saakashvili embarked on this risky venture without some sort of approval from the side of the United States," Churkin told Russian NTV television on Wednesday.

Meanwhile former Georgian President Eduard Shevardnadze said that Georgia made a "grave mistake" by advancing into the pro Russian breakaway province of South Ossetia.

Shevardnadze, who is a former Soviet foreign minister, also said the issue of Georgia in itself would not cause a new Cold War, as "the new Cold War has long since been instigated by the USA, through the Americans' so-called missile defence shield in the Czech Republic and Poland."