Fidel Castro has made a rare public appearance to launch his memoirs.

The increasingly reclusive former Cuban president spent six hours presenting the two-volume book to an audience in Havana.

State television showed a smiling, animated Castro wearing a dark tracksuit over a blue plaid button-up shirt. Audio of him speaking was not broadcast, but the Communist party newspaper Granma said he told attendees at the event on Friday that they would hear about "two books you haven't had any news of".

The memoir, Guerrilla of Time, is almost 1,000 pages long and covers Castro's life from childhood until December 1958, the eve of the triumph of the Cuban revolution. It is based on interviews with the journalist Katiuska Blanco.

"I have to take advantage now, because memory fades," Granma quoted Castro as saying.

The 85-year-old stepped aside provisionally in 2006 because of a life-threatening illness and retired permanently two years later, clearing the way for his younger brother and long-designated successor, Raúl, to take over.

Fidel Castro is seldom seen in public, though he did appear at a Communist party congress last April, holding the arm of an aide as he entered to tears and a standing ovation.

Granma said he mused about a wide range of topics on Friday, including visits from foreign dignitaries, world events and technological advances. He reportedly expressed deep opposition to private education and said Cuban leaders were wrong to think that simply by implementing socialism, all the island's economic problems would be solved. "Our duty is to fight until the last minute for our country, for our planet and for humanity," he was quoted as saying.

Castro generally speaks to Cubans through occasional columns called Reflections that are published in government-run newspapers and presented on television by newsreaders.