Cuban President Fidel Castro tumbled to the floor at a televised ceremony in Cuba Wednesday night, fracturing a knee and an arm. The incident set off a new round of speculation about the health of the iconic Communist leader who has governed the Caribbean island for 45 years.

Castro, 78, wearing his trademark olive military uniform, was helped to a chair and took a microphone to assure the shocked audience that he was "in one piece." The man who often has been quoted as saying, "Revolutionaries do not retire," vowed to continue working even in a cast.

"I ask your forgiveness for having fallen," Castro said, while some in the audience reportedly cried at the sight of their leader faltering.

Castro missed a single step and fell on a stage while returning to his seat after delivering a speech in the mausoleum that holds the remains of his fellow revolutionary, Che Guevara, in Santa Clara, 175 miles east of Havana.

Although Castro has shown signs of slowing down and fainted in public three years ago, he continues to travel throughout the country giving speeches. He has publicly declared that his brother, Raul, 74, would take over if he died.

"Anything that happens to Fidel has international repercussions," said Miguel Garcia Reyes, a Cuba specialist at the National Autonomous University of Mexico.

Castro's most recent stumble renewed speculation about how Cuba might change after his death. The island's relations with the United States have rarely been chillier than during the Bush administration.

In addition, its tense relations with Europe were underscored last week when Castro refused to allow three lawmakers to enter Cuba. A Spaniard and two Dutch legislators, who planned to meet with political dissidents, were turned back at Havana's airport.

In Washington, when the State Department spokesman, Richard Boucher, was asked Thursday whether he wanted to wish Castro a speedy recovery, he replied, "No."

"We obviously have expressed our views about what's broken in Cuba," Boucher said.

Many analysts say that Raul Castro and younger Cuban leaders seem more willing to open the island to foreign investment. Under Raul Castro, Garcia Reyes said, "the politics aren't going to change . . . but there might be more economic changes."

A recent series of hurricanes and a tightening of the four-decade U.S. embargo of the island during the Bush presidency have added to Cuba's economic problems. Power outages are common, and many basic foods and household necessities are hard to obtain.

A government statement said that Castro had broken his left knee and suffered a hairline fracture in his right arm, but that "his general health is good and spirits excellent." Ricardo Alarcon, president of the National Assembly, told reporters in Havana, "I am sure he will recover quickly and return to the fight."

Cuban television footage shows President Fidel Castro as he misses a step and tumbles while leaving the stage following a graduation speech in the central city of Santa Clara on Wednesday. Shortly after falling, the 78-year-old leader tries to reassure the audience. He suffered fractures of the left knee and right arm.