Miguel Díaz-Canel told crowds in Havana the US is trying to break down Cuba’s political system.
He announced the US seeks full control over Cuba.
Díaz-Canel branded US policies a type of political genocide during July 26 events.
He stressed this is a menace to the country's sovereignty.
Raúl Castro did not attend from the biggest rally.
Tensions are elevated as a result of sanctions and US political pressure.