Scrambling to find ways to punish Russia for its invasion of pro-Western Georgia, the United States and its allies are considering expelling Moscow from an exclusive club of wealthy nations and canceling an upcoming joint NATO-Russia military exercise, Bush administration officials said Tuesday.

But with scant leverage in the face of an emboldened Moscow, Washington and its friends have been forced to face the uncomfortable reality that their options are limited to mainly symbolic measures, such as boycotting Russian-hosted meetings and events, that may have little or no long-term impact on Russia's behavior, the officials said.

Click here to view photos of the conflict in Georgia.

With the situation on the ground still unclear after Russian President Dmitri Medvedev on Tuesday ordered a halt to military action in Georgia, U.S. officials were focused primarily on confirming a cease-fire and attending to Georgia's urgent humanitarian needs following five days of fierce fighting, including Russian attacks on civilian targets.

"It is very important now that all parties cease fire," Secretary of State Condoleezza Rice said. "The Georgians have agreed to a cease-fire, the Russians need to stop their military operations as they have apparently said that they will, but those military operations really do now need to stop because calm needs to be restored."

At the same time, however, President Bush and his top aides were engaged in frantic consultations with European and other nations over how best to demonstrate their fierce condemnations of the Russian operation that began in Georgia's separatist region of South Ossetia, expanded to another disputed area, Abkhazia, and ended up on purely Georgian soil.

"The idea is to show the Russians that it is no longer business as usual," said one senior official familiar with the consultations among world leaders that were going on primarily by phone and in person at NATO headquarters in Brussels, where alliance diplomats met together and then with representatives of Georgia.

A senior U.S. official, speaking on condition of anonymity to describe confidential conversations among the leaders of other nations, said European and other leaders have been blunt with Russia that it must withdraw its forces. Russian leaders have said they do not plan a long-term occupation, the official said. The official was not specific about whether Russia has offered a timeline for withdrawal.

"People are saying, 'You know you cannot stay,"' the official said. "We have been hearing from Russia, 'We don't want to stay."'

For now, the Bush administration decided to boycott a third meeting at NATO on Tuesday at which the alliance's governing board, the North Atlantic Council, was preparing for a meeting with a Russian delegation that has been called at Moscow's request, officials said.

On the table for future action is the possible cancellation or U.S. withdrawal from a major NATO naval exercise with Russia that is scheduled to begin Friday, the officials said. Sailors and vessels from Britain, France, Russia, and the U.S. were to take part in the annual Russia-NATO exercise aimed at improving cooperation in maritime security.

The exercise, which is being hosted by Russia this year, began a decade ago and typically involves around 1,000 personnel from the four countries, the officials said.

In the medium term, the United States and its partners in the Group of Seven, or G-7, the club of the world's leading industrialized nations that also includes Britain, Canada, France, Germany, Italy and Japan, are debating whether to effectively disband what is known as the G-8, which incorporates Russia, by throwing Moscow out, the officials said.

Discussions are also taking place on whether to revoke or review the May 2007 invitation to Russia to join the 30-member, Paris-based Organization for Economic Cooperation and Development, which consists primarily of established European democracies, the officials said.

The officials spoke on condition of anonymity because no decisions have yet been made and consultations with other countries involved are still under way.

Bush spoke on Monday and Tuesday with fellow G-7 leaders as well as the heads of democratically elected pro-Western governments in formerly Eastern bloc nations, some of which are among NATO's newest members and have urged a strong response to Russia's invasion of a like-minded country.

On Monday on his way home from the Olympics in China, Bush talked with British Prime Minister Gordon Brown, Lithuanian President Valdas Adamkus and Polish President Lech Kaczynski. He then called Georgian President Mikhail Saakashvili, the White House said. On Tuesday, he spoke with Italian Premier Silvio Berlusconi and German Chancellor Angela Merkel.

Rice, who returned early to Washington late Monday from vacation to deal with the crisis, held a second round of talks with foreign ministers from the Group of Seven countries in which they were briefed on European Union mediation efforts led by French President Nicolas Sarkozy, who met Tuesday with Medvedev in Moscow.

"They believe that they have made some progress and we welcome that and we certainly welcome the E.U. mediation," Rice told reporters at the White House.

Later, Saakashvili told reporters that he accepted the cease-fire plan negotiated by Sarkozy.

Despite the flurry of activity, there was still uncertainty about whether Russia had in fact halted its military action in Georgia, with reports of continued shelling of civilian and military sites.

The State Department on Tuesday recommended that all U.S. citizens leave Georgia in a new travel warning, saying the security situation remained uncertain. It said it was organizing a third evacuation convoy to take Americans who want to leave by road to neighboring Armenia. More that 170 American citizens have already left Georgia in two earlier convoys.

Just hours after Bush said in a White House address that the invasion had "substantially damaged Russia's standing in the world" and demanded an end to what he called Moscow's "dramatic and brutal escalation" of violence, Medvedev said he had ordered an end to military action.