(Reuters) - Venezuela’s state-run PDVSA has shipped 1 million barrels of oil to Cuba days after the United States imposed fresh sanctions on vessels and firms involved in exports to the island in an effort to halt oil trade between the political allies, according to a PDVSA document and tanker tracking data.

FILE PHOTO: The corporate logo of state oil company PDVSA is seen on a tank at an oil facility in Lagunillas, Venezuela January 29, 2019. REUTERS/Isaac Urrutia/File Photo

Tanker Trident Hope left Venezuela’s Jose port on Wednesday, and the S-Trotter tanker left on Thursday, both bound for Cuba’s state-run company Cubametales. The first one is carrying 600,000 barrels of Venezuela’s Zuata 300 crude and the second one is set to deliver 400,000 barrels of Merey crude.

Neither the Trident Hope nor the S-Trotter were among the vessels sanctioned by the United States last week. Three other vessels destined for Cuba were waiting to load with crude or refined products off Venezuela, the data showed.

One of them, the Despina Andrianna, carrying 500,000 barrels of crude for Cuba’s state oil company Cupet, was among the vessels sanctioned.

The shipments marked further defiance by Venezuela President Nicolas Maduro of Washington, which last week sanctioned 34 vessels owned or operated by PDVSA as well as two companies and a vessel that have previously delivered oil to Cuba, aiming to choke off a crucial supply of crude to the Communist-run island.

Those sanctions came on top of a previous round in January targeting PDVSA itself, part of the Trump administration’s effort to choke off revenue for Maduro’s socialist government and pave the way for Juan Guaido, the leader of the opposition-controlled National Assembly who invoked Venezuela’s constitution to assume an interim presidency, to take power.

Maduro argues Guaido is a puppet of the United States attempting to oust him in a coup. Venezuela’s Foreign minister Jorge Arreaza earlier this week said the OPEC-member nation plans to “fulfill its commitments” to Cuba. [nL1N21Q1HI]

The island’s Communist Party leader Raul Castro replied by saying Cuba would never abandon its ally even as U.S. President Donald Trump’s administration threatened more sanctions.

Venezuela has long sent subsidized crude to Cuba. The United States describes the arrangement as an “oil-for-repression” scheme in which Havana helps socialist Maduro weather an economic crisis and the power struggle with the opposition in exchange for fuel.

Neither PDVSA nor the oil ministry immediately responded to requests for comment.