According to the New York Times report, the tanker is owned by the Russian government and is carrying approximately 730,000 barrels of oil.
MarineTraffic, a ship-data provider, estimated that the tanker could reach Cuba by Monday night.
Cuba is in desperate need of oil and gas, as the Trump administration has been allowing some energy sales to private companies, but has effectively cut off supply to the government, which runs hospitals, schools, and public services.