WASHINGTON — Russia apparently is sabotaging airfields and other military infrastructure in Georgia as its forces pull back, in a deliberate attempt to cripple the already battered, American-trained Georgian military, an American official said today.

Reports from Georgia indicate that Russian forces are doing what they can to disable Georgia’s ability to fight a future conflict, the official said. The official spoke on condition of anonymity to describe incomplete but apparently convincing eyewitness accounts.

Explosions were heard near Gori today as a Russian troop withdrawal from the strategic city seemed to collapse. A fragile cease-fire appeared even more shaky as Russia’s foreign minister declared that the world “can forget about any talk about Georgia’s territorial integrity.”

Meanwhile America poured aid into the Georgian capital of Tbilisi in a Pentagon mission directly challenging Russia’s military moves to retake territory in the former Soviet republic. Secretary of State Rice launched emergency talks in France aimed at heading off a wider conflict.

Two aid flights were carrying cots, blankets, and medicine for refugees displaced by the weeklong fighting. The shipment arrived on a C-17 military plane, an illustration of the close America-Georgia military cooperation that has angered Russia.

Ms. Rice was meeting today with President Sarkozy of France, who has led the European pressure campaign on Russia, at his summer residence, Bregancon, near Toulon, France. From there she was going to Paris to meet with the French Foreign Minister, Bernard Kouchner, and tomorrow she plans to fly to Tbilisi. She had no plans to go to Moscow.

Ahead of the talks, Ms. Rice said that Russia’s military action in Georgia is a throwback to darker Cold War times.

“The message is that Russia has perhaps not accepted that it is time to move on from the Cold War and it is time to move to a new era in which relations between states are on the basis of equality, and sovereignty and economic integration,” Ms. Rice said yesterday.

The Bush administration is reeling from the near collapse of its closest friend among the former Soviet republics, a strategic Black Sea nation that is an emerging pathway for undeveloped energy reserves and that has worn its zeal for America and the West as a badge of honor.

As America mustered humanitarian aid for Georgia, President Bush demanded that Russia end all military activity inside its neighbor and withdraw all troops sent in recent days onto Georgian territory.

Mr. Bush announced that American military assets and personnel would be deploying into the conflict zone. Though they going there only on a humanitarian mission, he made a point of noting that “we will use U.S. aircraft, as well as naval forces” to distribute supplies. He warned Russia not to impede relief efforts in any way.

All this appeared designed to answer criticism that Mr. Bush has not done enough to stand by his 2005 pledge, made from the center of Tbilisi before tens of thousands of citizens, to “stand with” the people of Georgia.

Amid some fear that Russian troops may be setting up for some type of medium-term occupation of parts of Georgia or even have intentions to press on to its capital of Tbilisi, Mr. Bush promised yesterday to “rally the free world in the defense of a free Georgia.”

Speaking in grave tones in the Rose Garden, Mr. Bush decried Moscow’s apparent violation of a cease-fire agreement.

He demanded that Russia “keep its word and act to end this crisis.”

“The United States stands with the democratically elected government of Georgia and insists that the sovereignty and territorial integrity of Georgia be respected,” he said.

The president postponed today’s planned start of a two-week Texas vacation for a couple of days to monitor developments.

A Russian military convoy defied a cease-fire agreement yesterday and rolled through a strategically important city in Georgia, where officials claimed fresh looting and bombing by the Russians and their allies.

The Kremlin announced today that President Medvedev of Russia was meeting with the leaders of Georgia’s two separatist provinces, South Ossetia and Abkhazia.

“One can forget about any talk about Georgia’s territorial integrity because, I believe, it is impossible to persuade South Ossetia and Abkhazia to agree with the logic that they can be forced back into the Georgian state,” the Russian Foreign Minister, Sergey Lavrov, said.

Russia and its small neighbor had agreed Tuesday to a French-brokered cease-fire to end the dispute that began over two pro-Russian breakaway territories. America accuses Russia of pressing the war far beyond the initial conflict zone and threatening the democratically elected government in Georgia.

“I have to say that the reports are not encouraging about Russia’s respect for this cease-fire,” Ms. Rice said.

American officials have had difficulty determining exactly what’s happening on the ground in Georgia, despite considerable intelligence resources. American spy satellites have been repositioned to refocus on the conflict area.

Ms. Rice said Moscow is harming its standing in the world and eligibility for global clubs whose eligibility depends on responsible behavior, but she made no explicit threats about American retaliation.

“This is not 1968 and the invasion of Czechoslovakia where Russia can threaten its neighbors, occupy a capital, overthrow a government, and get away with it,” Ms. Rice said. “Things have changed.”