"Every nation in this chamber has the responsibility" to fight extremists, Bush said during his final address before the U.N. General Assembly.

He urged greater cooperation between member nations to "keep terrorist attacks from happening in the first place" and said nations must actively challenge tyranny.

"This mission requires clarity of vision," he said, adding that multinational organizations such as the United Nations must take a stand that "no cause can justify the taking of innocent life."

"Like slavery and piracy, terrorism has no place in the modern world," he said.

Bush also urged the United Nations to keep in place its sanctions against North Korea and Iran for their nuclear weapon aspirations.

Tyranny must be challenged as vigorously as terror, he said.

The nations of the United Nations "must stand united with the people of Georgia," Bush said, noting emerging democracies "will be watching to see how we respond" in upholding Georgia's territorial integrity and providing humanitarian relief.

The United Nations also must " adopt model of partnership, not paternalism" to help developing countries, Bush said.

He also said he would like to see an agreement that "would tear down trade barriers at the global level" and sought a renewed commitment to open economies and reject economic isolationism.

The United Nations "can be a powerful force of good," Bush said. "Together ... we can build a world that is freer, safer and better for generations that follow."