US Secretary of State Condoleezza Rice said Russia must honour its pledge to start withdrawing its troops from Georgia.
Ms Rice said Moscow had broken earlier promises to pull out.
Ms Rice told NBC’s ‘Meet the Press’ that Russian President Dmitry Medvedev had said several days ago that military operations would stop, but they did not.
Mr Medvedev also said that as soon as a ceasefire agreement was signed by Georgian President Mikheil Saakashvili, Russian troops would start withdrawing, but they did not, she added.
Ms Rice repeated warnings that Moscow's actions had put its integration into the global community at risk.
Sarkozy warns of 'serious consequences'
Mr Medvedev has reportedly informed French President Nicolas Sarkozy that his troops will begin withdrawing from Georgia from midday tomorrow.
Mr Sarkozy, who helped broker a ceasefire between Russia and Georgia in a dispute over two breakaway regions, said he spoke to his Russian counterpart by telephone.
The French president reportedly warned his Russian counterpart of ‘serious consequences’ if Russia failed to implement a peace deal with Georgia.
Mr Sarkozy told Mr Medvedev in a phone conversation of the ‘serious consequences that a failure to quickly and fully implement the deal would have on relations between Russia and the European Union,’ according to his office.
Mr Medvedev yesterday signed a six-point peace deal - brokered by the French president, whose country holds the EU rotating presidency - to end the fighting in Georgia.
The move came a day after Georgia’s pro-Western President Mikheil Saakashvili signed the agreement.
Earlier, the Russian military commander in Georgia said a phased withdrawal of his troops from the city of Gori was under way.
European journalists said there are fewer Russian tanks in Gori than several days ago, but Russian troops are manning checkpoints and armoured vehicles can be seen at many of the city’s main junctions.
Georgian security officials have said they believe that most Russian soldiers have left Gori, although they suspect that a redeployment is taking place.
