"It is a shame that some of our partners are not helping us but, essentially, are hindering us," Putin said. "I mean ... the transfer by the United States of a Georgian contingent in Iraq with military transport planes practically to the conflict zone."
Putin's emotional speech said the U.S. was wrong to blame Russia for the outbreak of war.
"The very scale of this cynicism is astonishing -- the attempt to turn white into black, black into white and to adeptly portray victims of aggression as aggressors and place the responsibility for the consequences of the aggression on the victims," he said.
The U.S. appears to have little leverage over Russia, however, in part because the Bush administration needs Russian cooperation in its negotiations with Iran over its nuclear program.
After Saakashvili signed a cease-fire agreement , he later held a news conference to accuse Russia of trying to overthrow his government.
"Russia made clear the goal of this operation is the regime change in Georgia, change of democratically elected government," he claimed. "It is quite clear what is happening. We are in the process of an invasion, occupation and annihilation of an independent democratic country."
He called the Russian offensive a "pre-planned, cold blooded, meditated murder of a small country."
Saakashvili compared Russia's push to its invasion in 1968 of Czechoslovakia and Afghanistan in the 1990s.
"As we speak, there are people being shot, killed," he said. He later added, "What else can happen for the world to wake up and see what's at stake?"
Russia and Georgia accused each other today of carrying out campaigns of ethnic cleansing of the breakaway provinces.
Despite facing an overwhelming military force, Saakashvili, when asked what he would do if Russian forces moved toward Tblisi, said, "We have no plan of surrender."
EU officials hope to convince Russia to also sign the cease-fire deal. The foreign ministers from the G-7, representing the world's seven largest economic powers, called on Russia to accept the cease-fire with Georgia, following a conference of all the ministers, including U.S. Secretary of State Condoleezza Rice.
Besides backing its Georgian allies, the U.S. is closely watching the conflict because of Georgia's status as a major conduit of oil to Black Sea ports. Any disruption to Georgia's main pipeline could send world oil prices soaring again, and, in turn, kick up the price of gas at U.S. pumps. So far, the pipeline has been untouched.
The outbreak of fighting has reportedly claimed the lives of 2,000 civilians caught in the crossfire, and thousands more are homeless, with many fleeing the area. The capital of South Ossetia has been devastated by shelling.
Russia has deployed ships off the Georgian coast and claims to have sunk a Georgia missile ship, while swarms of Russian planes bombed sites near the Georgian capital of Tbilisi for the fourth straight day.
Russia claimed that Georgian artillery again shelled the South Ossetian capital Tskhinvali, and claimed that two more of its planes have been shot down, bringing the total of lost Russian planes to four.
Russia insists that it was withdrawing from some of its positions in Georgia, but people remain fearful and expect more attacks.
The shooting began when Georgian troops moved last week to reassert control of its breakaway province, South Ossetia. Georgian troops briefly occupied the South Ossetian capital before a powerful Russian force chased them back into Georgia.
The Associated Press and Reuters contributed to this report.