Cuba's government claims it foiled a plot aiming at destabilizing the country by preventing the chief of the Organization of American States traveling to the island.
OAS Secretary General Luis Almagroto was slated to attend an award ceremony organized by dissidents.
The opposition group, which the government called "anti-Cuban and illegal," had invited Mr Almagroto to Havana to honor him for shining a light on violations of human rights in the Americas.
Cuba, which views the Washington-based OAS as an imperialist instrument of the United States denied Almagro and other international invitees visas and issued a blistering statement.
Cuba accused Almagro of "an ambition agenda of auto promotion with attacks against progressive governments like those of Venezuela, Bolivia and Ecuador."
In a letter to the dissidents, Almagro said he had assured the Cuban authorities he did not have an anti-Cuban agenda.