National Security Adviser John Bolton may have inadvertently revealed a potential next move by the Trump administration in the Venezuela crisis Monday when photographers captured a note on a legal pad that read: "5,000 troops to Colombia."

Sources tell Fox News that the White House is considering pre-positioning U.S. forces in Venezuela's western neighbor in case they are needed. However, the sources said that no such move is imminent.

"As the president has said, all options are on the table," a White House spokesperson told Fox News. The National Security Council declined to comment on the note, while the Pentagon referred questions to Bolton.

VENEZUELA OPPOSITION LEADER CALLS FOR MORE PROTESTS

Bolton was holding the legal pad in full view of the White House press corps while he and Treasury Secretary Steven Mnuchin announced the imposition of sanctions on Venezuela's state-owned oil company PDVSA, a move aimed at increasing the pressure on disputed president Nicolas Maduro to step aside in favor of opposition leader Juan Guaido.

"We have continued to expose the corruption of Maduro and his cronies, and today's action ensures they can no longer loot the assets of the Venezuelan people," Bolton said, adding that he expected Monday's actions would result in more than $11 billion in lost export proceeds over the next year.

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Bolton also warned the Maduro government that it would face a "significant response" if any harm came to U.S. diplomatic personnel, Guaido or the opposition-held National Assembly.

The U.S. has recognized Guaido as Venezuela's interim president, along with more than 20 other countries. Russia, China, Turkey, Iran and Cuba are among the countries backing Maduro.

Fox News' John Roberts, Jennifer Griffin and The Associated Press contributed to this report.