Cuban Foreign Minister Bruno Rodriguez on Tuesday accused the United States of meddling in the island's domestic affairs.
Rodriguez tweeted that the United States "urges its embassy in Cuba to interfere in the internal affairs of a sovereign country that will not allow it."
Such "illegal actions ... violate the Vienna Convention, the agreement for the re-establishment of relations and Cuban and US laws," he added.
Havana said Washington is using the case of Jose Daniel Ferrer, who is regarded as a counter-revolutionary in Cuba but as a human rights activist in the United States, as an excuse to intensify hostility towards the island state.
Cuban state daily Granma said the US embassy in Havana is a "fundamental vehicle" to interfere in Cuba's domestic affairs.
Charge d'Affaires of the US Embassy in Havana Mara Tekach was behind Ferrer, trying to create division and confusion among the Cuban population, the daily said.
US-Cuba ties have deteriorated under the Trump administration, which has rolled back the detente initiated by former US President Barack Obama.