Casting a bad omen for better ties with Washington, Venezuela's President Hugo Chavez said on Thursday he will keep fighting the U.S. "empire" and warned President-elect Barack Obama against "throwing stones."

Chavez said Obama accused Venezuela in a speech earlier this week of exporting terrorism and obstructing progress in Latin America.

"Look what he has started saying, what's next for us? We'll keep fighting imperialism whether the chief of the empire is black or white," Chavez told hundreds of supporters in Caracas.

Chavez is a fierce critic of U.S. foreign policy and during the administration of President George W. Bush the former paratrooper accused Washington of organizing a 2002 coup against him. In September, he expelled the U.S. ambassador.

Venezuela, an OPEC member, is a key crude oil supplier to the United States, and Chavez has repeatedly threatened to cut off supplies even though the United States is his country's main customer.

Washington accuses Venezuela of supplying guns and money to neighboring Colombia's Marxist guerrillas, a charge Chavez denies. CIA Director Michael Hayden said on Thursday that falling world oil prices could be positive because they might fracture Chavez's government.

Despite warning Obama, Chavez said he hoped relations with the United States would improve under the new president.

"If he respects Venezuela, he will receive a respectful reply," he said. "There is still time for Mr Obama to rectify when he assumes the presidency."

Chavez has been in power for a decade and is popular for welfare programs and building health clinics. He wants to change the constitution so he can run for president again in 2012 but Venezuela's opposition has gained strength in the last two years and Chavez could struggle to win voter approval for the reform.