HAVANA - Fidel Castro temporarily relinquished his presidential powers to his brother Monday night and told Cubans he will undergo surgery.

Cuban President Fidel Castro, left, and his brother, Minister of Defense Raul Castro, attend a Cuban Parliament session in the Palace of Conventions in this July 1, 2004, file photo in Havana, Cuba. It was announced, Monday, July 31, 2006, that Fidel Castro has temporarily relinquished presidential power to his brother Raul due to illness. [AP]

The Cuban leader said in a letter read live on television by his secretary that he had suffered gastrointestinal bleeding, apparently due to stress from recent public appearances in Argentina and Cuba.

Because of that illness, Castro said he was temporarily relinquishing the presidency to his brother and successor Raul, the defense minister, according to the statement read by Carlos Valenciaga.