Cuban strong man Fidel Castro has resigned from the Communist Party's central committee, formalising a gradual retreat from spotlight that started in 2006.

The 84-year-old leader wrote in a newspaper column that his brother Raul Castro, who has been running the affairs of the country since 2006, is aware of his decision not to be part of the top leadership of the party.

Castro underwent an intestinal surgery in 2006, and was away from public life for months on end. Raul took charge of the country in his brother's absence. In 2008, Fidel officially stepped down as president.

Fidel called on the younger generation of leaders to turn around the country’s economy. The new generation should now rectify and change without hesitation everything that should be rectified and changed,” Fidel wrote on the website of

“There is no margin for error in this moment in human history,” Fidel said. He is not attending the Sixth Congress of the Cuban Communist Party, where a new leadership will be voted to power.

The economic future of the country is in focus at the party Congress where delegates are discussing the means to counter a crippling US sanctions regime and high debts foreign exporters.