Pictures of Fidel Castro were last aired on Cuban TV in June
The minister said Mr Castro maintained "permanent" contact with leaders of the Communist party and the government.
His comments come amid growing rumours about the health of Mr Castro, who has not been seen in public since he had intestinal surgery in July 2006.
The illness forced Mr Castro, 81, to hand over power to his brother, Raul.
"Fidel is doing very well," Mr Perez Roque told reporters during his visit to Brazil. The minister added that Mr Castro was "disciplined in his recovery process".
Earlier this month, Mr Castro issued a statement saying he was fighting relentlessly for a full recovery.
Uncertainty
Since his emergency surgery, Mr Castro has only been seen in photographs and short video broadcasts on Cuban state television.
In July, Mr Castro did not appear at Cuba's National Revolution Day celebrations - for the first time in 48 years.
Secrecy surrounding his condition has fuelled rumours about the extent of his health problems and his eventual political future.
However, Cuban officials have repeatedly said he will eventually resume office.
Cuban President, Fidel Castro. 
Rumors began circulating today in Miami, Florida that Fidel Castro, the President of Cuba, may be dead. The rumor has been reported to have started on Wall Street in New York City.

''PerezHilton.com'' was the first to "break" the news, saying that an official announcement on Castro's death would be coming at 2:00 p.m. (local time), but no announcements were made and there has been no confirmations of his death.

Castro turned 81 on August 13 and shortly after, reports began to circulate that his health was on a downward track, but the Cuban government states that Castro is doing well.

"Fidel is doing very well" and is "disciplined in his recovery process," said Felipe Perez Roque, Cuba's Foreign Minister in a statement to the press.