In an escalating war of words, President Bush on Tuesday urged Russia to reconsider its "irresponsible decision" to shower independent status on two breakaway Georgian provinces.
Already rebuffed by Russian President Dmitry Medvedev, Bush warned Russia to change course and respect the borders of its Georgian neighbor.
"Russia's action only exacerbates tensions and complicates diplomatic negotiations," the president said in a statement from Texas, where he is otherwise spending a quiet vacation.
Despite mounting international condemnation, Russia showed no sign of backing down. The U.S. is reviewing its relationship with Russia but has imposed no sanctions.
Medvedev said Tuesday that his country will grant diplomatic recognition to the separatist regions of Abkhazia and South Ossetia. He said Georgia forced Russia's hand by trying to gain control by force in the smaller of the two areas, South Ossetia, on Aug. 7.
"This is not an easy choice but this is the only chance to save people's lives," Medvedev said Tuesday in a televised address a day after Russia's Kremlin-controlled parliament voted unanimously to support the diplomatic recognition.
Bush shot back that Russia's move violates both United Nations resolutions and the six-point cease-fire deal that Russia, under Medvedev's watch, signed with Georgia to end a war.
"We expect Russia to live up to its international commitments, reconsider this irresponsible decision, and follow the approach set out (in the cease-fire deal)," Bush said.
The White House says the U.S. will use its veto power on the U.N. Security Council to ensure that the two separatist provinces remain part of Georgia in the eyes of the world.
Secretary of State Condoleezza Rice said that any push by Russia to do otherwise will be "dead on arrival" at the United Nations.
The rhetoric underscored the stakes of a once-obscure territorial dispute that has mushroomed into a Cold War-style conflict between the United States and Russia.
Russian tanks and troops drove deep into undisputed Georgian territory in a five-day war this month that Moscow saw as a justified response to a military threat in its backyard.
Separately, meanwhile, Medvedev warned Tuesday that his country may offer a military response to a U.S. missile shield in Europe. He said the deployment of an anti-missile system close to Russian borders "will of course create additional tensions."
"We will have to react somehow, to react, of course, in a military way," Medvedev was quoted as saying Tuesday by the RIA-Novosti news agency.
The White House sought to emphasize that Russia's conflict was with the world, not just with the United States. Several foreign leaders criticized Russia's action on the two provinces.
"Russia is making, I would say, a number of irrational decisions," said White House spokesman Tony Fratto.
"We hope that they hear the loud voices from the international community and understand that it's not in their long-term interests to take these kinds of actions," he said.
Vice President Dick Cheney leaves next week on a trip that includes a stop in Georgia; Fratto said no U.S. officials plan to go to Russia to appeal directly to leaders there.
Bush said the U.S. condemns Russia's actions; just a day earlier, he had appealed to Medvedev to refrain from recognizing the two provinces as independent, to no avail.
Campaigns weigh in
Barack Obama, who will become the Democratic presidential nominee this week, condemned Russia's move and said the U.S. should convene a Security Council meeting to do the same. He did not say how the Council would do that, given Russia's status as a permanent member.
Republican John McCain's wife was in Georgia, visiting refugee centers filled with ethnic Georgians who fled villages and neighborhoods in South Ossetia.
"The only place these people want to be is home, and they can't go home because of what has happened to them and because of the situation that the Russians have caused," Cindy McCain said in brief remarks Tuesday outside one of the centers in Tbilisi.
John McCain has been a strong critic of Russia and has proposed expelling Russia from the Group of Eight club of the world's major developed democracies.
In Washington, State Department spokesman Robert Wood said the U.S. is looking at a variety of options to respond.
"We're not trying to escalate anything," Wood said when asked whether disagreement between the West and Russia would jeopardize international cooperation. But, he added, "We obviously can't allow what Russia's done to go without there being some consequences."
He would not provide details about possible punishment the U.S. is considering.
Meanwhile, the United States dispatched a military ship bearing aid to a Georgian port city still patrolled by Russian troops.