"The oil industry is the backbone of the Venezuelan economy," Maduro said on state television.
"The U.S. empire for a long time ... has intended to sabotage the oil industry and defeat the (Venezuelan) government, in order to steal the oil."
Neither the U.S. embassy in Caracas nor the State Department in Washington immediately responded to requests for comment.
Maduro said he had ordered an investigation and the delivery of a letter of protest to the U.S. charge d`affaires.
"We cannot accept this," added Maduro. "It is offensive, a violation of international law."
The United States and Venezuela have had a troubled relationship since Maduro`s predecessor Hugo Chavez came to power in 1999. They have not shared ambassadors since 2010.
Last week, a New York court indicted two nephews of Maduro`s wife, Cilia Flores, who are suspected of importing cocaine.
Earlier this month, Venezuela said a U.S. Coast Guard plane violated its air space and that other such planes were circulating close to the South American country.
Government critics say the anti-U.S. rhetoric is intended to cloak domestic problems - inflation thought to be in triple digits, shortages of basic goods and soaring crime rates - ahead of Dec. 6 legislative elections.
The oil industry, which accounts for 96 percent of Venezuela`s foreign income, has been hit by falling prices. This week the price of the country`s oil basket fell to its lowest in 2015, at $34.55 per barrel.
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