Miguel Díaz-Canel spoke to crowds in Havana the US is trying to break down Cuba’s political system.
He announced Washington wants complete control through the nation.
Díaz-Canel branded US 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 did not attend from the biggest rally.
Tensions are elevated due to sanctions and US political pressure.