This executive order states otherwise.
Marco Rubio is being completely disingenuous about the US blockade. The US is conditioning oil sales to private entities only. Meaning, no oil can be provided for any public sector infrastructure. They are doing this to try and force Cuba to privatize all of its essential infrastructure...effectively undermining any "Socialist" programs in the country. This includes hospitals, schools, water and sewage management, electricity...everything.
This is how he can say, with a straight face, that it's the Cuban government's fault that people there are without fuel. Technically, all they have to do to let the oil through...is to sell off all of their public assets to private entities. Easy peasy.
It's like putting a gun to someone's head and telling them they have a choice. Either do what I say, or die.
But, sure. It's totally the Cuban government's fault that this is happening.