President Donald Trump on Thursday threatened new tariffs on countries supplying oil to Cuba, escalating a pressure campaign against the Communist-run island.

The move, authorized by an executive order under a national emergency declaration, did not specify any tariff rates or single out any countries whose products could face U.S. tariffs.

Emboldened by the U.S. military’s seizure of ousted Venezuelan President Nicolas Maduro in a deadly raid earlier this month, Trump has repeatedly talked of acting against Cuba and pressuring its leadership.

Trump said this week that “Cuba will be failing pretty soon,” adding that Venezuela, once the island’s top oil supplier, has not recently sent oil or money to Cuba.

Trump has used tariff threats as a foreign policy tool throughout his second term in office.

Cuba’s president said this month Washington had no moral authority to force a deal on Cuba after Trump suggested the Communist-run island should strike an agreement with the U.S.

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(Reporting by Kanishka Singh and Jasper Ward in Washington; Editing by Ross Colvin and Lisa Shumaker)