Miguel Díaz-Canel spoke to crowds in Havana the US is attempting to break down Cuba’s political system.
He said Washington wants full control across the island.
Díaz-Canel described American policies a form of political genocide during July 26 events.
He emphasised this is a danger to the country's right to govern.
Raúl Castro stayed away from the main rally.
Tensions remain high as a result of sanctions and US political pressure.