Miguel Díaz-Canel told crowds in Havana the US is trying to undermine Cuba’s political system.
He said America aims for full control through Cuba.
Díaz-Canel described US policies a form of political genocide during July 26 events.
He emphasised this is a menace to the country's sovereignty.
Raúl Castro stayed away from the biggest rally.
Tensions remain high due to sanctions and US political pressure.