The US secretary of state has warned Russia that it risks isolation abroad if does not observe a ceasefire with Georgia and withdraw its troops, BBC reported.
Condoleezza Rice is to visit France for talks with President Nicolas Sarkozy, who currently chairs the EU, before visiting Georgia itself on Friday.
The US has begun delivering aid by air to the ex-Soviet republic.
Washington is showing unwavering support for Georgia in its conflict with Russia, a BBC correspondent notes.
Russian forces briefly moved out of the breakaway Georgian province of South Ossetia on Wednesday to destroy military hardware at an abandoned Georgian military base in the nearby town of Gori.
Thousands of Russian troops remain in South Ossetia since they drove out a Georgian force which tried to regain control of the de facto independent province in a surprise attack one week ago.
They are also deployed in force in Abkhazia, Georgia's other breakaway province, where separatists ejected Georgia's remaining troops this week.
Dispatching Ms Rice to Europe, President George W Bush called on Moscow to withdraw its forces from Georgian territory.
"The (US) stands with the democratically elected government of Georgia, insists that the sovereignty and territorial integrity of Georgia be respected," he said at the White House on Wednesday, flanked by the secretary of state and Defence Secretary Robert Gates.
"We expect Russia to meet its commitment to cease all military activities in Georgia, and we expect all Russian forces that entered Georgia in recent days to withdraw from that country," he said.
Ms Rice said Russia faced international "isolation" if it refused to respect the truce.
There was, she said, a "very strong, growing sense that Russia is not behaving like the kind of international partner that it has said that it wants to be".
Ms Rice is to discuss with Mr Sarkozy the five-point peace plan he personally brokered with Russian President Dmitry Medvedev and Georgian President Mikhail Saakashvili on lightning visits to Russia and Georgia on Tuesday.
A US military transport plane landed in Tbilisi airport on Wednesday evening, delivering what the US said was medical supplies, bedding and other items for internally displaced people.
The US special envoy to the region, Matthew Bryza, said the consignment was the first of many that would be arriving by sea and air.
The provision of US aid to Georgia follows a promise by President Bush that the US military would play a role in delivering emergency supplies to Georgia.
Kim Ghattas, the BBC's correspondent at the US state department, says that while Washington has been warning Russia of the consequences of its military action in Georgia, so far little has happened apart from the cancellation of a joint military exercise.
But the view from Washington is that Russia has more to lose from a deterioration in ties with the West.
US officials insist that Moscow does care if concrete moves are taken to isolate it on the international scene, our correspondent says.