Those comments came a week after a new government video showed a more robust image of the bearded rebel leader who in late July said that he had undergone intestinal surgery and was provisionally ceding power to his younger brother.
"He's getting better each day," the younger Castro said in brief comments to news media at the opening of an international book fair Thursday. "He's exercising much. He has a telephone at his side and uses it a lot."
Raul Castro made a surprise appearance Thursday evening at the annual book fair — an event his 80-year-old brother often attended in past years.
"He's consulted on the most important questions," Raul Castro said of Fidel. "He doesn't interfere, but he knows about everything.
"Luckily, he doesn't call me much," Raul joked, saying his older brother usually called on Vice President Carlos Lage and Foreign Minister Felipe Perez Roque.
The 75-year-old Raul traded in his typical olive green uniform for a gray jacket over a pair of blue pants for the event at a Spanish fortress across the bay from Havana.
Arriving at the opening in a small bus, the younger Castro was accompanied by Culture Minister Abel Prieto.
Raul Castro's appearance at a purely cultural event was seen as highly unusual, and it was not immediately clear if it would mark the emergence of a new, more public persona. His informal comments to the press were the first since he assumed provisional power.
Since Fidel stepped down, Raul Castro has appeared in public and given speeches only when he has deemed it necessary.
In past years, the older brother had often enjoyed attending the opening of the book fair, arriving last year with his good friend and ally, Venezuelan President Hugo Chavez.
Fidel Castro's illness remains a state secret, but Cuban officials have denied past U.S. government reports that he suffered from fatal cancer. A Spanish newspaper reported last month that the leader had diverticular disease, a weakening of the walls of the colon common in older people.
A Jan. 30 video showed a stronger Fidel Castro who looked like he had gained weight during his convalescence. He looked far more gaunt and pale during a previous video released in late October.
In recent days, Chavez and some Cuban officials made encouraging assessments about Fidel's health. Venezuela's ambassador to Cuba Ali Rodriguez Araque said earlier Thursday that Castro had resumed eating after a long period of being unable to ingest solid foods.