WASHINGTON — President Bush consulted Tuesday with fellow leaders in Eastern and Western Europe about the crisis in the former Soviet republic of Georgia while aides scrambled to evaluate a Russian promise to stop attacking its neighbor. The White House also rejected a Russian call for Georgian President Mikhail Saakashvili to step down.

Earlier, Russian President Dmitri Medvedev ordered a halt to its military action in Georgia, saying the campaign had brought security in its South Ossetia region that is close to Moscow.

"The aggressor has been punished and suffered very significant losses. Its military has been disorganized," Medvedev said in a nationally televised statement.

His order came just hours after Bush's strongest statement on the fighting since it began at the end of last week. He demanded that Russia withdraw its troops from Georgia, end what he called a "dramatic and brutal escalation" of violence, and accept international mediation to end the crisis. Bush said Russia's actions had "substantially damaged Russia's standing in the world."

With Georgia insisting that Russian forces were still bombing and shelling, White House spokesman Tony Fratto said Tuesday it was too early to comment on Medvedev's move. "We are trying to get an assessment of what a halt means and whether it is taking place, of course," the spokesman added.

Typifying the administration's dilemma, a planned late-morning White House briefing by national security adviser Stephen Hadley was postponed "until further notice" due to ongoing developments in Georgia and in Moscow, where French President Nicolas Sarkozy was meeting with Russian officials on behalf of the West.

In the meantime, Bush continued a round of discussions with allies. On Monday on the way home from China, Bush talked with British Prime Minister Gordon Brown, Lithuanian President Valdas Adamkus and Polish President Lech Kaczynski. Former Iron Curtain nations such as Lithuania and Poland — now democracies and staunch U.S. allies — have urged the West to come down hard on Russia in its conflict with Georgia.

Bush called Saakashvili after his Rose Garden statement, Fratto said. And on Tuesday morning, he spoke with Italian Premier Silvio Berlusconi and German Chancellor Angela Merkel.

American officials are working with U.S. allies in Europe and elsewhere, as well as with the Russians, to defuse the situation diplomatically.

Secretary of State Condoleezza Rice cut a resort vacation short and returned to Washington Monday night to help deal with the crisis. She planned a conference call with colleagues from the Group of Seven leading industrialized nations. The group — the U.S., Britain, Canada, France, Germany, Italy and Japan — has been expanded in recent years to include Russia, but Moscow has not been invited to participate in the discussions on the crisis.

There were no immediate plans to go to either Russia or Georgia. A State Department envoy is in Georgia.

The G7 has issued a call similar to Bush's for Russia to accept a truce and agree to mediation as conditions deteriorated and Russian troops continued their advances into Georgian territory.

But despite the tough talk from Bush and others, there has been no specific threat of any consequences Russia might face if it ignores the warnings.

Also Tuesday, Russian Foreign Minister Sergey Lavrov said that Saakashvili must leave office, and demanded that Georgian troops stay out of the breakaway South Ossetia region for good.

In Washington, Fratto countered: "President Saakashvili is the duly elected president of a sovereign democratic nation and so the determination of him as president is his decision and a decision for the Georgian people and not for any outside nation to make demands on whether he is the appropriate person."

A senior U.S. official said Monday that the United States and its allies suspected Russia had been planning an invasion for some time and deliberately instigated the conflict through attacks on Georgian villages by pro-Russian forces in South Ossetia despite outwardly appealing for calm and promising to rein in the separatists.

The official, who spoke on condition of anonymity to discuss internal administration deliberations, said there were numerous "unpleasant precedents" for the current situation, including the 1979 Soviet invasion of Afghanistan and the 1968 Soviet invasion of Czechoslovakia.

"The escalation on the part of the Russia was disproportionate to their stated intentions," Fratto said.

Meanwhile, the State Department said it has evacuated more than 170 American citizens from Georgia, including all Peace Corps volunteers. Two convoys carrying the Americans, along with family members of U.S. diplomats based in Georgia, were said to have left Tbilisi on Sunday and Monday for neighboring Armenia.

The department on Tuesday recommended that all U.S. citizens leave Georgia. In a new travel warning, it said the security situation throughout Georgia remained uncertain and that it is organizing a third evacuation convoy to take Americans who want to leave by road to neighboring Armenia.

Associated Press writers Jennifer Loven, Anne Gearan and Pauline Jelinek contributed to this report.