Secretary of State Condoleezza Rice has demanded Russia end its actions in Georgia, saying the country is facing international isolation for "brutally" pushing its military operations in the region.
"Those operations must stop and must stop now," Rice said during a briefing with reporters.
"This is not 1968 and the invasion of Czechoslovakia where Russia can threaten a neighbour, occupy a capital, overthrow a government and get away with it," Rice said. "Things have changed."
Rice spoke hours after U.S. President George W. Bush called on Russia to end all military activity in the former Soviet republic and withdraw its forces.
"The United States stands with the democratically elected government of Georgia and insists that the sovereignty and territorial integrity of Georgia be respected," Bush said.
The president added that a massive U.S. humanitarian effort was already in progress.
Rice, who will travel to Paris and the Georgian capital of Tbilisi to help with diplomatic efforts to end hostilities, said there are worrisome reports from Georgia that Russia has not lived up to its pledge of ending military operations.
"That will only serve to deepen the isolation into which Russia is moving. It will only serve to deepen the very strong growing sense that Russia is not behaving like the kind of international partner that it has said that it wants to be," Rice said.
She said "Russia has brutally pushed this military operation well beyond the bounds of anything that might have related to South Ossetia" which calls into question Russia's "suitability for all kinds of activities that it has said that it wants to be a part of."
Rice also said Russia needs to respect the U.S. aid effort to help the people of Georgia.
"We expect the air routes, the land routes, the sea routes to be open for humanitarian activities," Rice said.
She reaffirmed the Pentagon's statement that it is not the United States' intention to take control of port facilities.
Meanwhile, Russian troops have left the Georgian town of Gori near South Ossetia, but are not moving towards Tbilisi, Georgia's deputy interior minister said Wednesday.
"I'd like to calm everybody down. The Russian military is not advancing towards the capital," Ekaterine Zguladze said, according to a report from Reuters. Earlier media accounts spoke of a convoy of Russian vehicles spotted on the road to the capital from Gori.
That was shortly after Georgian President Mikheil Saakashvili accused Russia of sending 50 tanks into the central Georgian city of Gori despite an agreed-upon ceasefire calling on both sides to retreat to positions they held before fighting began six days ago.
Gori, which sits on Georgia's only significant east-west road, is about 25 kilometres over the South Ossetian border into Georgia and has faced heavy bombardment in recent days.
Human Rights Watch weighed in on Wednesday with its assessment of the conflict, saying it has witnessed South Ossetian fighters looting ethnic Georgians' houses and has recorded multiple accounts of Georgian militias intimidating ethnic Ossetians.
The news of Russian troop movements came less than a day after Georgia accepted a French-brokered ceasefire previously agreed to by Russia to end a conflict that broke out Friday as Georgian forces moved in to retake South Ossetia from Russian-backed separatists.
Moscow responded swiftly and forcefully to the Georgian military action, sending thousands of troops into South Ossetia and the larger separatist province of Abkhazia. While South Ossetia's independence is not recognized internationally, it has close ties to Russia, and almost all of its 70,000 residents have Russian passports.
Meanwhile, European Union foreign ministers debated on Wednesday sending peacekeeping monitors to South Ossetia to help uphold the ceasefire.
French Foreign Minister Bernard Kouchner told reporters that many of the 27-member European Union states are ready to send monitors to Georgia, but not before the United Nations passes an appropriate resolution.
Also on Wednesday, Russian Foreign Minister Sergei Lavrov said his country's "peacekeepers" will remain in South Ossetia, an apparent violation of the ceasefire terms.
Both sides back French plan
On Tuesday, Russian President Dmitri Medvedev ordered a halt to his country's military action in Georgia and gave his support to the provisional ceasefire, saying the plan "points the way towards gradual normalization" in the wartorn region.
Following his meeting with French President Nicolas Sarkozy, Saakashvili announced that he would accept a slightly altered version of the plan.
The changes — approved by Medvedev — included removing a reference to talks on the future status of South Ossetia, Saakashvili and Sarkozy said during a joint news conference early Wednesday.
International Co-operation Minister Bev Oda announced Tuesday that Canada is contributing as much as $1 million in aid to provide Georgians affected by the conflict with emergency medical care, safe water and other basic items, such as blankets and clothing.