Castro warned, however, that he still might not recover from his July 31 surgery for gastro-intestinal bleeding but he promised "to fight for it."
Castro's first public statement since his surgery two weeks ago came on his 80th birthday. Venezuelan president and close Castro confidant, Hugo Chavez, extended Sunday birthday wishes to the ailing Cuban leader and said he would soon visit him.
Before undergoing the surgery, Castro ceded power to his brother and Defense Minister Raul Castro.
His decision to step down -- the first such action in 47 years -- prompted widespread celebration in the U.S. Cuban community and speculation that Castro might never return to power.