Havana: Convalescing Cuban leader Fidel Castro sent a written message to the National Assembly on Friday saying he had "clung" to power in his younger days, but that life had taught him to change his attitude.

Castro, who handed over governance to his brother Raul after surgery in July 2006, hinted last week he may give up his formal leadership in a letter describing his duty as "not to hold to positions and less to obstruct the path of younger people".

Cuba's National Assembly could formalise Castro's retirement as head of state when it approves the members of the executive Council of State at its new session in March.

Empty seat

Since falling ill, the 81-year-old Castro has only appeared in official photographs and pre-taped videos and it is unclear whether he will resume office. If he is too ill, the assembly may formally appoint Raul Castro or someone else as successor.

"What the foreign press in Cuba have most reported in recent days has been the phrase where I expressed ... that I am not a person who clings to power. I could add that I was once, for the excesses of youth and lack of conscience," Castro said in a statement read out at the assembly session, where the younger Castro, 76, sat next to his brother's empty seat.

"What changed me, life itself, through the deepening of the thoughts of [Cuban hero Jose] Marti and the classics of socialism," he wrote.

Castro has been nominated to run again for the assembly and his brother says he is now well enough that party delegates back his running again for an assembly seat.