Castro's brother, Raul Castro, 76, is widely tipped to take over the helm of the country, though Vice President Carlos Lage, 56, and Foreign Minister Felipe Perez Roque, 42, are seen as credible if longer-shot younger-generation candidates.
The National Assembly of People's Power is to make its choice after seating its 614 deputies at 10am on Sunday.
It usually carries out its deliberations behind closed doors, under the direction of its speaker, Ricardo Alarcon. On Sunday, he is to open the historic session with a brief speech to which the media have been invited.
The National Assembly of People's Power officially designates the 31 members of the Council of State, including its president who serves as head of state, a post created in 1976. The council also names a first vice-president, who is currently Raul Castro.
The deputies in the new national assembly were elected on January 20.
Their duty on Sunday is to work out the new composition of the Council of State, whose list of members was last fixed in 2003, under the previous assembly.
Of the 31 positions, only 27 are currently filled, following the sacking or deaths of the others. Eleven of the seats are held by members of the political bureau of the Communist Party.
His brother, Raul Castro, 76, who has served as provisional president for the last 19 months, is widely considered the likely successor.
But analysts believe that Cuba's powerbrokers could turn to a new generation of leaders after nearly half a century of Castro rule. Vice President Carlos Lage, 56, is seen as a potential successor as is Foreign Minister Felipe Perez Roque, 42.
The US vowed to keep the economic and diplomatic screws on Cuba after Castro's announcement, saying it would not be lifting its nearly 50-year-old embargo "any time soon."
US President George W Bush said Castro's resignation should begin a "democratic transition" in Cuba, starting with the release of political prisoners and culminating with free and fair elections.
But Venezuelan President Hugo Chavez, Castro's ideological heir apparent, said the revolution started by his Cuban mentor was bigger than the man who led it.
"The Cuban revolution does not depend on one person, on a juncture, nor on circumstance," he said late Tuesday as he opened a new hospital. "Fidel is not giving up or abandoning anything – he is occupying the post that he has to fill in the Cuban revolution and the Latin American revolution," he said.
"Fidel always was in the vanguard. Men like Fidel never retire," he said.
Castro took power in 1959 after his band of bearded guerrilla fighters ousted dictator Fulgencio Batista.
Güncelleme Tarihi: 21 Şubat 2008, 14:35