The United States on Sunday accused Russia of stalling its military pullback in Georgia, but the Bush administration is not rushing to repudiate Moscow for its actions. The White House is struggling to figure out the best way to penalize Russia. It doesn't want to deeply damage existing cooperation on many fronts or discourage Moscow from further integrating itself into global economic and political institutions. At the same time, US officials say Russia can't be allowed to get away with invading its neighbor. Fighting broke out after Georgia launched a massive barrage Aug. 7 to try to take control of the separatist province of South Ossetia, which is heavily influenced by Russia. The Russian army quickly overwhelmed Georgia's forces, then drove deep into the country, bombed Georgian ports and military installations and tied up an east-west highway through the nation. "There's no doubt there will be further consequences," said Secretary of State Condoleezza Rice, who briefed President George W. Bush on the fast-changing crisis over the weekend at his Texas ranch. She returned to Washington on Sunday and is flying to Europe on Monday to talk with NATO allies about what message the West should send to Russia. Rice is then flying to Warsaw, where she will sign a formal agreement with Poland for the establishment of a missile interceptor site there. Moscow has protested the U.S. plans for such a base so close to its borders. Russia can't use "disproportionate force" against its neighbor and still be welcomed into the halls of international institutions, Rice said. "It's not going to happen that way," she said. "Russia will pay a price." But neither Rice nor Defense Secretary Robert Gates would be specific about what punitive actions the US or the international community might take. "We're going to take our time and assess what further consequences there should be to the relationship," Rice said. The United States wants to take a tough stance against Russia, but there is much at stake. "The facts are that the United States has to work with Russia on Iran, on nuclear problems of proliferation, on a whole raft of trade issues at a time in which the United States has a huge domestic deficit," said Sen. Richard Lugar, the senior Republican on the Senate Foreign Relations Committee. And holding open the prospect of taking steps against Russia gives the United States some leverage in pushing Russia to withdraw from Georgia. But nothing is expected to happen in a hurry, and the United States doesn't want to turn the conflict into a fight between the former Cold War rivals. "There is no need to rush into everything," Gates said. "We don't want to do it unilaterally. "I think there needs to be a strong, unified response to Russia to send the message that this kind of behavior, characteristic of the Soviet period, has no place in the 21st century," he said. Russian President Dmitry Medvedev said Russian troops will begin leaving Monday, but made no mention of leaving the separatist province at the heart of the conflict between the countries. The Bush administration is hopeful yet skeptical that Russia will honor its pledge to withdraw troops quickly from Georgia under terms of a cease-fire it signed Saturday. "My own view is that the Russians will probably stall and perhaps take more time than anybody would like," Gates said. "I think we just need to keep the pressure and ensure that they abide by the agreement that they've signed and do so in a timely way." Konstantin Kosachev, chairman of the Russian parliament's foreign affairs committee, said Russian forces will be out of Georgia "sooner or later." Echoing Bush's call to withdraw U.S. troops from Iraq depending on conditions on the ground, Kosachev said: "If I would ask you ... `How fast the American forces can leave Iraq?' ... the answer would be, as soon as we have guarantees for peace and security there. The same answer would be toward this situation."