UNITED NATIONS — Russia’s war with Georgia is widening, drawing in Ukraine, the Baltic states, Poland, and even America.

President Bush yesterday, flanked by his defense secretary, Robert Gates, announced he would send American aircraft and naval vessels to the region on what he described as a humanitarian mission aimed at aiding Georgia. Ukraine restricted movement of Russian navy ships based at a Black Sea port, Bloomberg News reported. And Poland, a NATO ally of America, advanced in its negotiations with America for a missile defense site that Russia has fiercely opposed.

The leaders of Estonia, Latvia, Lithuania, Poland, and Ukraine appeared at a rally in Tbilisi, where the president of Poland, Lech Kaczynski, said Russia “has shown its true face,” according to press accounts.

With Russian troops surrounding key Georgian cities while pro-Russian paramilitary forces loot inside, diplomats are haggling in back rooms over the fine points of a provisional cease-fire agreement. The rhetoric in Washington, Moscow, and Tbilisi is escalating, dimming hopes for peace and raising concerns of a wider conflict.

Although Western diplomats insist Russia has indicated it would agree to talk with Georgia’s foreign minister, public statements from Moscow indicate it is averse to any negotiations with the elected government of President Saakashvili. The suspicion that Russia’s aim is to undermine, and perhaps unseat, the pro-Western leader in Tbilisi is one of the largest threats to the prospects for peace.

“The United States of America stands with the democratically elected government of Georgia,” Mr. Bush said yesterday. “We insist that the sovereignty and territorial integrity of Georgia be respected.” But Mr. Saakashvili told CNN, “Frankly, my people feel let down by the West.”

Russian troops are advancing “well beyond the conflict zone” of Georgia’s breakaway regions of South Ossetia and Abkhazia, Mr. Saakashvili said, hours after agreeing “in principle” to a six-point plan to end the war. The agreement was brokered by President Sarkozy, but a European diplomat yesterday described it as “broad” and said that in the next few days the Security Council would have to flesh out the details.

“Definitely, there is work to do,” the diplomat, who spoke on condition of anonymity, said. Several other diplomats predicted hardships in the diplomacy, citing yesterday’s violent outbreaks in the two disputed regions and other parts of Georgia. They also said that several of the original six points were not agreed to by the Russians and Georgians. “There is an agreement on five and a half points,” said one diplomat early yesterday.

The original six-point plan included a call for leaders in Tbilisi and Moscow to negotiate a permanent agreement over the breakaway regions once a cease-fire is implemented. A six-point plan that was published by the European foreign ministers in Brussels instead called for “international talks on the security and stability arrangements in Abkhazia and South Ossetia.” The reason, according to diplomats, was that Moscow declined to negotiate directly with the Georgian government.

“Lunatics’ difference from other people is that when they smell blood it is very difficult to stop them, so you have to use surgery,” President Medvedev said of Mr. Saakashvili soon after announcing his agreement to Mr. Sarkozy’s pact Tuesday night.

Appearing at the Rose Garden, Mr. Bush questioned the motives of Russia’s “ongoing” action in Georgia. He warned Moscow that its assault on Georgia puts “its aspirations at risk” as it vies for memberships in trade organizations and a seat among the top seven democracies.

Russia retorted immediately. “We understand that this current Georgian leadership is a special project of the United States, but one day the United States will have to choose between defending its prestige over a virtual project or real partnership which requires joint action,” the Russian foreign minister, Sergey Lavrov, said.

“This is not 1968 and the invasion of Czechoslovakia where Russia can threaten a neighbor, occupy a capital, overthrow a government, and get away with it,” Secretary of State Rice said yesterday. But it was clear that after agreeing to Mr. Sarkozy’s plan, Russia’s military missions in Georgia accelerated. According to reports cited by Mr. Bush, the Black Sea port city of Poti was attacked by Russian troops and naval forces. The central city of Gori, which controls the east-west highway, was also surrounded by Russian tanks and troops.

Speaking on Fox News Channel, General Wesley Clark, who commanded NATO forces in the Balkans in the 1990s, described an old tactic employed by Russia, which entailed the use of allied paramilitary troops to loot and pillage a city as Russian forces surround it, while at the same time making public promises to rein the marauders in. “I spoke today with Rice and she told me there are reports of acts of looting in Gori, that illegal groups are looting the city and Russian troops are doing nothing,” Mr. Lavrov said yesterday. “If any such facts prove true, we will react in the most serious way.”

Mr. Bush said he was sending Ms. Rice to France to bolster Mr. Sarkozy’s mediation efforts. “I’ve also directed Secretary of Defense Bob Gates to begin a humanitarian mission to the people of Georgia,” Mr. Bush said, adding it would include American aircraft and naval forces. “We expect Russia to honor its commitment to let in all forms of humanitarian assistance,” and keep all roads, ports, and airways open for that purpose, he said.