Karen Vasquez, 44, walked out of jail in Cuba on Sunday, part of a deal brokered by the Vatican under which the Biden administration would loosen sanctions on the communist-run island, while Havana would release more than 500 people from its jails who are considered political prisoners by Washington.

The Cuban Observatory of Human Rights, based in Spain, in a statement Tuesday expressed 'great concern about the possible cancellation, pause or delay of the release of political prisoners in Cuba.' The Biden administration in its final days had removed Cuba from the US terror list in return for a promise to release 553 people.