|Castro has been suffering from ill health for the past couple of years [File: AFP]|
Cuba's national assembly is likely to nominate Raul Castro as president when it meets on February 24.
Castro's retirement brings an end to a political career that survived the Cold war, assassination attempts by the CIA, nine US presidents and the breakup of the Soviet Union.
He came to power in 1959 in a Communist revolution that overthrew the then president Fulgenico Bautista.
He became an icon of socialism and a staunch opponent of the US which led to a crippling political and economic blockade of the Caribbean island.
Al Jazeera's correspondent David Hawkins said the US would welcome the permanent departure from power of Castro, but with Raul in position, relations between the two countries will remain severed.
"Castro is a living piece of history while his brother Raul does not have his same stature," Hawkins said.
Castro is admired in the developing world for standing up to the US, but is accused by his opponents of suppressing freedom.
Source: Al jazeera and agencies