The resignation of Cuban leader Fidel Castro may open the door for his brother, Raul, to officially take over the communist government. VOA's Brian Wagner has this report from Miami.

The announcement by Fidel Castro comes only days before officials are to select the island's top ruling body, the Council of State. The 81-year-old leader is expected to remain on the 31-member ruling council, but says he will not compete for the top post.

Cuban state television read a letter from Mr. Castro in which he said he is physically unable to fulfill the duties of president.

In the letter, Mr. Castro says he will not seek and will not accept the post of president and commander-in-chief.

For months, Mr. Castro's failing health has raised questions about the political future of the island and the man who ruled it for nearly 50 years. The Cuban president underwent intestinal surgery in July 2006, and handed over power temporarily to his brother, Raul.

Many analysts say Raul, 76, is the most likely to succeed Fidel Castro as Cuba's president and would retain many of his older brother's political and economic policies.

In Miami, critics of the Cuban government welcomed the news of Mr. Castro's resignation early Tuesday.

Democracy activist Ramon Saul Sanchez said the announcement is good news for advocates of democratic change in Cuba.

"Frankly the fact that Castro has ceded all political powers at this point is an inspiration not only to us but to those inside of Cuba, the elements of change within the regime itself, that want to see some other direction for the country," he said.

Sanchez says he does not believe a transition to Raul Castro will bring immediate change to the lives of Cuba's 11 million people. But he says pressure for broad reform on the next Cuban leader, from inside Cuba and outside, will grow.

"This is the beginning of a new direction, probably a first step in a new direction, that could end up in more reforms," said Sanchez.

Earlier, President Bush said the international community should work with Cuba's people to bring about a democratic transition on the island.