Fidel Castro said that the late Venezuelan President Hugo Chavez was the "best friend" he had during his 47 years as Cuba's head of state.

"Today I keep a special memory of the best friend I had in my politically active years - who, very humble and poor, forged himself in the Bolivarian Army of Venezuela - Hugo Chavez Frias," said Castro in a lengthy text dated Aug. 13, the former president's 87th birthday.

"Many questions still need to be answered about Hugo Chavez, from the most important moment of his existence, when he took possession of his post as President of the Republic of Venezuela," added Castro in the text published in the communist island's official media on Wednesday with apparently recently-taken photographs of the leader of the Cuban Revolution.

Castro, who left the Cuban presidency in 2006 due to a serious intestinal illness, praised Chavez as a "man of action and ideas" and added that those who knew him "know the priority he gave to those ideological challenges."

"He was surprised by a type of very aggressive illness that made him suffer a lot, but he faced it with great dignity and deep sadness for the relatives and close friends he loved so much," said the Cuban leader regarding Chavez's death from cancer on March 5.

In the three-page text, Castro also devoted space to reviewing issues like Cuba's military cooperation with the Soviet Union, the 1962 Cuban missile crisis, the November 1963 assassination of U.S. President John F. Kennedy and he even mentioned the plans to "involve" Cuba in his killing. EFE