HOUSTON (Reuters) - The U.S. government has notified foreign partners of Venezuela's state oil company PDVSA of the imminent cancellation of authorizations that allow them to export Venezuelan oil and byproducts, sources close to the decision by President Donald Trump's administration said on Saturday.

In recent years, former President Joe Biden's administration granted the authorizations to secure Venezuelan oil supplies to refineries from Spain to India as exceptions to the U.S. sanction regime on the South American country.

The companies that had received licenses and comfort letters from Washington include Spain's Repsol, Italy's Eni, France's Maurel & Prom, India's Reliance Industries and U.S. Global Oil Terminals.

Most companies had already suspended imports of Venezuelan oil following Trump's imposition this week of secondary tariffs to buyers of Venezuelan oil and gas, according to sources and vessel tracking data.

Repsol, Eni, Maurel & Prom, Reliance and the U.S. State and Treasury departments did not immediately reply to requests for comment. Global Oil could not be reached for comment.

Last month, Trump said a key license to U.S. producer Chevron ( CVX ) to operate in Venezuela and export crude to the U.S. would be canceled. Days later, the U.S. Treasury Department ordered the company to wind down operations, and last week extended the deadline to May 27.

The withdrawal of the most important U.S. license for Venezuela's energy industry had sent a signal of Washington's change of policy towards Venezuela as Trump's government curbs migration, with special focus on Venezuelans illegally in the U.S.

It was not immediately clear if all PDVSA foreign partners were given the same deadline of May 27 to wind down operations.

U.S. Secretary of State Marco Rubio said this month that foreign companies in Venezuela would receive new guidance.

Venezuelan President Nicolas Maduro, whose 2024 re-election was not recognized by Washington, has criticized the sanctions, saying they amount to an "economic war."