By Marianna Parraga

(Reuters) – Venezuelan state-run oil company PDVSA is taking steps to remove at least two American executives from the board of directors of its U.S. refining subsidiary, Citgo Petroleum Corp, according to people close to the matter.

Citgo is facing unprecedented challenges to its finances and management after the U.S. government last week imposed tough sanctions on Petroleos de Venezuela, known as PDVSA, designed to prevent oil revenue from going to leftist President Nicolas Maduro. The United States and dozens of other nations have refused to recognise Maduro, viewing his reelection last year to another six-year term as fraudulent.

Venezuelan’s self-proclaimed president Juan Guaido is setting up bank accounts with U.S. help that would take income accrued by Citgo, Venezuela’s top foreign asset, to finance an interim government. Maduro has denounced Guaido as a U.S. puppet who is seeking to foment a coup.

The board of Houston-based Citgo includes at least two U.S. citizens, Art Klein and Rick Esser, as well as Venezuelans Asdrubal Chavez, Frank Gygax, Nepmar Escalona, Simon Suarez and Alejandro Escarra, according to one of the people familiar with the matter.

Citgo also has an executive board that includes the refiner’s general managers, its corporate treasurer and the controller, and other vice presidents.

PDVSA and Citgo did not respond to requests for comment. Esser and Klein did not immediately reply to emails and phone calls seeking comment on their status.

It was unclear if PDVSA’s board has already approved the changes at Citgo’s board and who would replace the American executives.

(Reporting by Marianna Parraga in Mexico City; Additional reporting by Deisy Buitrago and Corina Pons in Caracas; editing by Gary McWilliams and Leslie Adler)