George Bush calls for more unity in the United Nations
George W Bush has accused Russia of violating the UN's charter by invading Georgia, in his final speech to the world body as US president.
Mr Bush urged world leaders gathered at UN in New York to "stand united in our support of the people of Georgia".
In a wide-ranging speech, Mr Bush also urged the international community to continue the fight against terrorism.
He also gave an assurance that the US was taking decisive action over the current global economic crisis.
Mr Bush's speech touched on the themes of his presidency.
He accused Iran and Syria of continuing to sponsor terrorism, saying they were growing more isolated.
He also urged the UN to enforce sanctions on North Korea and Iran over their nuclear programmes.
On terrorism, the president warned that the world's leaders could not simply pass resolutions condemning terrorist acts after they had happened.
He said that instead, terrorism should be confronted with a "clarity of vision".
Referring to Russia's recent military action in Georgia, he said: "We must stand united in our support of the people of Georgia.
Economic issues are expected to dominate this year's assembly
"The United Nations charter sets forth the equal rights of nations large and small. Russia's invasion of Georgia was a violation of those words."
Mr Bush's comments came hours after Georgia said it had shot down a Russian reconnaissance drone flying over its territory.
It said the unmanned plane was downed south of its de facto border with the breakaway region of South Ossetia.
Russia dismissed the claim as a "media provocation by Georgia".
Mr Bush also assured world leaders that the US was acting decisively to contain the current global economic crisis.
He said he was confident that his plan to buy up the bad debt blocking the flow of credit would be passed by the US Congress "in the urgent timeframe required".
Speaking after Mr Bush, French President Nicolas Sarkozy said Europe's message to Russia was that it could not accept the use of force to settle disputes.
Mr Sarkozy also called for a summit of world leaders to be held by the end of the year to discuss lessons learned from the global financial turmoil.
And he said the G8 group of leading industrialised countries should be expanded to include China, India, South Africa, Mexico and Brazil.
World financial problems were also a major theme of the address by UN Secretary General Ban Ki-moon when he opened the annual assembly.
He said the financial turmoil put at risk the achievement of the UN-agreed Millennium Development Goals set in 2000 to halve global poverty by 2015.
He added that the crisis demanded a new approach with less "uncritical faith in the 'magic' of markets".
"The global financial crisis endangers all our work - financing for development, social spending in rich nations and poor, the Millennium Development Goals," he told the meeting.