Venezuelan President Hugo Chavez today called President Bush "the devil" and the "world dictator" on the floor of the U.N. General Assembly, then asserted that the United Nations suffers from a "mortal disease" because it is dominated by the "North American empire."

"Yesterday, ladies and gentlemen, from this rostrum, the president of the United States, the gentleman to whom I refer as the devil, came here, talking as if he owned the world," Chavez told the General Assembly. "I think we could call a psychiatrist to analyze yesterday's statement made by the president of the United States."

Speaking from the podium where Bush spoke a day earlier, Chavez said he can still smell the "sulfur" -- a reference to the scent of Satan.

U.S. officials declined to comment on Chavez's speech.

"We're not going to address that kind of comic strip approach to international affairs," said John Bolton, the U.S. ambassador to the United Nations.

Chavez had gotten personal with Bush before, calling him "Mister Devil," among other names, but never in such a rarified forum.

Today, he called the U.S. president "the spokesman of imperialism" and accused him of trying to "preserve the current pattern of domination, exploitation and pillage of the peoples of the world."

"The world is waking up," Chavez said. "I have the feeling, dear world dictator, that you are going to live the rest of your days as a nightmare because the rest of us are standing up, all those who are rising up against American imperialism."

Bush, in his address to the General Assembly yesterday, chastised the governments of several countries -- notably Iran, Syria and Sudan. But he did not mention Venezuela, and he did not direct any personal insults at any leaders, or even mention them by name.

Taking aim at the United Nations, Chavez told the annual meeting of the world body that has drawn dozens of world leaders: "I don't think anybody in this room could defend the system. Let's be honest. The U.N. system born after the Second World War collapsed. It's worthless."

Later, at a news conference, Chavez called for a "re-foundation" of the United Nations.

"There is no way to save it," he asserted. "There is no room for reform. This is a mortal disease. . . . The system was created for a certain era, but the era is over. It was designed for" a time when the U.S. and Soviet Union dominated world affairs.

In rhetoric often used by his friend, ailing Cuban President Fidel Castro, Chavez referred to the United States as an "empire" that has been a scourge to poor nations.

"The United States empire is on the way down and it will be finished in the near future for the good of all mankind," Chavez said. "I hope that we will never have to face another empire. That's why I believe we need to re-found the system . . . I don't know whether it should be called the United Nations again or not."

Chavez said a committee of world leaders should be formed to determine the future of the United Nations.

The future, Chavez told reporters, "will not be easy because the North American empire, the imperialism of the White House, is enormous. . . . In this struggle of David and Goliath, we are David. And Goliath will fall down."

Chavez's address follows of series of strident anti-American speeches at the United Nations by U.S. adversaries, including Iranian President Mahmoud Ahmedinejad and Sudanese President Omar al-Bashir. Together, they represented an emboldened alliance of oil-rich states who defied U.S. demands to change their policies on a range of issues, including the development of nuclear technology to the role of U.N. peacekeepers in Darfur.

"The president of the United States came to talk to the peoples -- to the peoples of the world," Chavez told the general assembly. "What would those peoples of the world tell him if they were given the floor? What would they have to say?

"I think I have some inkling of what the peoples of the south, the oppressed people think. They would say, 'Yankee imperialist, go home.' "

These comments came days after Chavez returned from Cuba, which hosted a meeting of the nonaligned movement, an organization of states that is dominated by developing countries.

Today, Chavez chided opponents of the Cuban regime who expected Castro to die quickly after his government disclosed he had a serious illness last month.

" . . . They thought, 'Oh, Fidel was going to die.' But they're going to be disappointed because he didn't," said Chavez, who visited Castro in his hospital room. "And he's not only alive, he's back in his green fatigues."

Lynch reported from the United Nations. Staff writer William Branigin contributed to this report.