Displaying deep annoyance, Chavez asked hypothetically in his comments before the National Assembly what would happen if oil-exporting Venezuela cut off shipments to the United States.
Chavez also accused a U.S. Jewish rights group of joining a Washington-backed smear campaign after it denounced him for making anti-Semitic remarks. Chavez insisted those remarks had nothing to do with Jews and were badly misconstrued.
His comments came after the U.S. Embassy in Madrid announced that the United States had denied permission for the sale of planes, citing concerns about a Venezuelan government that it said had "grown progressively more autocratic and antidemocratic."
"What is this if not evidence of the horrific imperialism that the government in Washington wants to impose on the world?" Chavez said.
In Washington, State Department spokesman Sean McCormack said the United States concluded the proposed transfers were not consistent with the country's interests.
"We're concerned that this proposed sale of military equipment and components to Venezuela could contribute to destabilization in Latin America and have made that view clear to the Spanish, Venezuelan and other governments in Latin America," McCormack said.
Chavez has accused the United States of plotting to overthrow him and has warned any invasion would be defeated. Washington has strongly denied any such plans, but Chavez says Venezuela, the world's No. 5 oil exporter whose main customer is the United States, must be prepared.
"Every day we send them 1.5 million barrels of oil," said Chavez. "What would happen if tomorrow I were to say that no ship leaves for the United States?"
He made it clear the idea was not being considered at present, but was possible if the United States tried to oust him.
U.S. law authorizes the government to prevent a country from transferring military equipment purchased in the United States to a third country.
Chavez called the U.S. concerns ridiculous, saying "these are transport planes."
Spain said Friday it did not share the U.S. concerns and would go ahead with the deal, removing the U.S.-made components and replacing them with parts made elsewhere.
Spain agreed in November to sell Venezuela the planes and eight patrol boats for $2 billion, despite U.S. threats at the time to oppose the transfer. It would be Spain's largest-ever defense deal, involving 10 C-295 transport planes and two CN-235 patrol planes, as well as four ocean patrol boats and four coast patrol vessels.
Officials have said neither the boats nor the transport planes were armed and that the patrol planes were equipped only for self-defense.
But McCormack said Friday that the U.S. was rejecting the entire sale.
The U.S. government has also expressed concern about Russia's planned sale of helicopters and 100,000 Kalashnikov rifles to Venezuela starting early this year. But Russia has said it too is going ahead with the deals.
Chavez also lashed out at The Simon Wiesenthal Center, a U.S.-based Jewish organization that demanded he apologize for remarks made in Christmas Eve speech.
"The world has enough for all," Chavez said, according to a transcript of the Dec. 24 speech. "But it turned out that some minorities, descendants of those who crucified Christ, descendants of those who threw Bolivar out of here and also crucified him in their own way in Santa Marta, there in Colombia, a minority took the world's riches for themselves."
Chavez said those comments had nothing to do with Jews, but rather with poverty and the expulsion of the 19th-century independence hero Simon Bolivar from Venezuela.
The Wiesenthal Center claimed similar remarks have long been used to persecute Jews, but Chavez noted that a prominent leader of Venezuela's Jewish community had issued a statement saying the community does not believe Chavez was targeting Jews.
"These were the classic characterizations leveled against the Jews for two thousand years," Rabbi Marvin Heir, founder of the center, said Friday. "A president of a country who did not mean to harm Jews or to speak in a bad way of Jews would not have made those remarks."
Separately, Chavez denied Friday that he was meddling in upcoming Peruvian elections. Chavez's Peruvian counterpart Alejandro Toledo has criticized Chavez' open support of Ollanta Humala, a nationalist former military officer, in the campaign to choose his successor this April.
"I'm incapable of calling for (Peruvians) to vote or not to vote" for one candidate over another, Chavez said. "But Toledo has said something very grave — that Chavez destabilizes the continent."
Chavez, who says he is leading a socialist revolution for the poor, is up for re-election in December. He remains popular amid high oil prices that have funded his social programs and helped bring economic growth of 9.4 percent last year.