The goal is to build up a government of its own that will challenge the internationally recognized regime linked to the regular army, which risks further deepening the division in the war-torn country.
The rebels' prime minister will be Mohamed Hassan al-Ta'ayshi, who will now begin to appoint ministers. The Presidential Council is led by RSF commander Mohamed Hamdan Dagalo.
The military formed a government in May and appointed former UN official Kamil Idris as prime minister, in an attempt to take steps towards civilian rule.
Sudan's army and RSF have been fighting each other for over two years of civil war. In May, the military drove the rebels away from the area around the country's capital, Khartum.
The war broke out in April 2023. Tens of thousands of people have been killed and over 14 million have been displaced from their homes.