The president of Venezuela, the world's fifth-largest oil exporter, called for stability in international crude prices, implying they should be lower than they are but blaming a near-constant rise on what he called war-mongering by the United States.
Hugo Chavez, an "anti-imperialist" former army colonel who misses no opportunity to blast Washington, commented after a stop in Rome on his way to the EU-Latin America summit in Vienna.
"The U.S. empire is the cruellest, most immoral, murderous and savage empire that ever has existed on this planet," he said. He expressed the wish "that it die this century, because if it lasts another century, it will ruin the Earth."
After meeting with Pope Benedict, Chavez told a press conference that OPEC, after years of trying, had achieved oil price stability by the early 2000s, mentioning the cartel's range of $22-28 per barrel.
"And we were happy, because we'd put an end to those uncertainties in which the bottom would fall out of the price, or it would suddenly rise," he said.
But he blamed the 2003 U.S.-led invasion of Iraq - which he termed "immoral, illegal and unjust" - for doing more than anything else to upset world oil markets.
More recently, he said U.S comments about punishing Iran, another major crude producer, have spurred price hikes.
"Do the Iranian people, or any other people, have the right to have nuclear energy?" he asked. "Who arrogates for themselves the right to say, 'This country may have nuclear reactors, but this other one may not?'"
Of U.S. President George W. Bush he said: "Every time he opens his mouth, the price of oil goes up a dollar."
The Venezuelan leader recommended that his U.S. counterpart "stay on his ranch and be quiet." "God willing, (oil) prices will stabilize," Chavez said, expressing the hope that an upcoming meeting of OPEC in Venezuela would contribute to that end.
During his private meeting with the Pope Benedict XVI has told Venezuela's President Hugo Chavez that he is concerned about religious reforms in the largely Catholic nation.
A Vatican spokesman says Pope Benedict was worried about a proposal to ban teaching religion in Venezuelan schools.
The pontiff also asked that the nation's health programs "respect life," an apparent reference to abortion, which the church opposes.
The Venezuelan leader assured the pope of his commitment to "overcome every tension in respecting the legitimate rights of all."
Mr. Chavez often quotes from the bible during speeches. But he has clashed with the Catholic leadership in Venezuela, referring to it as a "cancer."