TBILISI, Georgia — Demonstrating Washington’s commitment to beleaguered Georgia, Vice President Cheney flew in today and condemned Russia for what he called an “illegitimate, unilateral attempt” to redraw Georgia’s borders by force.

Speaking during a closely watched trip to this American-allied South Caucasus nation, Mr. Cheney also assured President Saakashvili of Georgia that the America was “fully committed” to his country’s efforts to join NATO.

“Georgia will be in our alliance,” Mr. Cheney said.

One of the American administration’s most hawkish figures and a longtime critic of Russia, Mr. Cheney was visiting three ex-Soviet republics that are nervous about Moscow’s intentions — Georgia, Azerbaijan, and Ukraine.

His trip signaled to Moscow that America will continue to cultivate close ties with Georgia and its neighbors even after Russia showed it was not afraid to use its military against countries along its border.

“America will do its duty to work with the governments of Georgia and our other friends and allies to protect our common interests and to uphold our values,” Mr. Cheney said in a joint appearance with Mr. Saakashvili.

“Russia’s actions have cast grave doubts on Russia’s intentions and on its reliability as an international partner,” Mr. Cheney added.

He told Mr. Saakashvili that America was at Georgia’s side “as you work to overcome an invasion of your sovereign territory and an illegitimate, unilateral attempt to change your country’s borders by force, that has been universally condemned by the free world.”

On the eve of Mr. Cheney’s arrival, the White House announced a $1 billion commitment to help the small but strategically located nation recover from its war with Russia.

“The free world cannot allow the destiny of a small independent country to be determined by the aggression of a larger neighbor,” Secretary of State Rice told reporters in Washington.

In his remarks today, Mr. Cheney also thanked Georgia for sending troops to Iraq. Georgia has been the third largest contributor of troops to the American-led operation there.

“Now it is the responsibility of the free world to rally to the side of Georgia,” Mr. Cheney said

Mr. Saakashvili, meanwhile, said Georgia was committed to a peaceful resolution of its disputes with the breakaway regions of South Ossetia and Abkhazia. Russia, which has given military, political, and financial support to the two areas, has recognized both as independent nations.

A day earlier in Azerbaijan, Mr. Cheney said Washington has “a deep and abiding interest” in the region’s stability. Georgia hosts a critical oil pipeline that brings 1 million barrels a day from the Caspian Sea shores to Turkey, and on to Western Europe.

Mr. Cheney planned to make the massive American aid package a major highlight of his meetings in Tbilisi, but it will likely leave unanswered the question of potential American aid to rebuild Georgia’s military.

Since the war in Georgia in early August, Russia has boldly asserted it has what President Medvedev called “privileged interests” in its sphere of influence, which includes the former Soviet states in the Caucasus.

Military aid from America, with the help of some Western European countries, was key to transforming the Georgian army and navy from their ragged post-Soviet condition into a credible fighting force. Depleted by the war, it will need more Western aid to rebuild the military if it is to join NATO.

But angry Russian officials have repeatedly said that American military aid was instrumental in emboldening Georgia to try to retake South Ossetia by force on August 7. During the five days of fighting that followed, Russian forces routed the Georgian military from South Ossetia and drove deep into Georgia.

American officials have placed at least part of the blame for the war on Russia, but new American military aid to Georgia would further aggravate relations between Washington and Moscow, which are already at a post-Cold War low.

Russia has condemned the American use of warships to deliver aid to Georgia as a form of gunboat diplomacy. The flagship of the American 6th Fleet in the Mediterranean, the USS Mount Whitney, arrived in the Black Sea yesterday with a cargo of aid.

The American aid package is about the same as the estimate given by Prime Minister Lado Gurgenidze of how much damage Georgia’s economy suffered from the war.

Mr. Cheney arrived from neighboring Azerbaijan, the starting point for a major oil pipeline that crosses Georgia and ends in Turkey.

Because of the trip’s itinerary, “we see this as a very clear sign that alternative energy routes and sources will be secured,” the Georgian national security council head, Alexander Lomaia, told The Associated Press.

The pipeline is the only direct route for Europe-bound Caspian oil to bypass Russia. Caspian oil also goes to Georgian ports by another pipeline and by rail.

Mr. Cheney is expected to spend only about four hours in Georgia. The stopover contrasts with President Bush’s exuberant visit in May 2005, when Mr. Bush spoke to a vast crowd in Tbilisi with Mr. Saakashvili.

Mr. Medvedev, meanwhile, harshly criticized America and urged Washington to “reassess its relationship with the Georgian regime.”

“The United States has actively helped Georgia build its military machine and pumped money and weapons into that,” Mr. Medvedev said in an interview with Italy’s RAI television.

“Regrettably, at some point they have given Mr. Saakashvili a carte blanche for any actions, including the military actions,” he said.