HAVANA -- Fidel Castro said Tuesday that he was stable and in good spirits after surgery, according to a statement read on state television, as the communist government tried to impose a sense of normalcy on the island's first day in 47 years without the bearded leader in charge.
Castro, who temporarily handed power to his younger brother Raul on Monday night after undergoing intestinal surgery, indicated the operation was serious when he said: "I can not make up positive news."
But he said his health was "stable," and "as for my spirits, I feel perfectly fine," according to the statement read by moderator Randy Alonso on a daily public affairs program. He said it would take some time for doctors "to provide a verdict" on his recovery.
Castro apologized for not giving more details, but said the threat posed to his government by the United States means his health must be treated as "a state secret."
Castro expressed his gratitude for the good wishes he received from leaders and supporters around the world, and called on Cubans to remain calm as they carried out their daily routines.
"The country is prepared for its defense," he said in the statement. "Everyone needs to struggle and work."
Across the Florida straits in Miami, where hundreds of thousands of fleeing Cubans have settled, boisterous celebrations Monday night gave way to speculation about what would happen in Cuba when Castro dies. Car horns still blared, but some cautioned the celebrations may have been premature.
Parliament Speaker Ricardo Alarcon called the celebrations "vomit-provoking acts" led by "mercenaries and terrorists."
He told the government's Prensa Latina news service that the Cuban leader is known for fighting to the very end, but said his "final moment is still very far away."
Raul Castro, the island's acting president, was nowhere to be seen as Cubans began to worry about what comes next.
"Everything's normal here -- for the moment," said hospital worker Emilio Garcia, 41, waiting for a friend at a Havana hotel. "But we've never experienced this before -- it's like a small test of how things could be without Fidel."
Cuban dissidents kept a low profile while watching for signs of Castro's condition. It was unknown when or where the surgery took place or where the 79-year-old leader was recovering.
The main newscast on state-run television ran a string of man-on-the-street interviews with Cubans wishing Castro well and professing confidence in the revolution's staying power. The anchor said Castro had the people's "unconditional support."
Cubans were stunned when Castro's secretary read a letter on state television Monday night announcing their leader was temporarily turning over power to his younger brother, the island's defense minister and the president's designated successor.
In the letter, Castro, who turns 80 on Aug. 13, said doctors operated to repair a "sharp intestinal crisis with sustained bleeding."
Alarcon said Castro made a point of delegating all responsibilities when his doctors told him to rest -- a decision he said was made by a man "who was completely conscious and able to adopt these resolutions."
Castro had been seen frequently in recent days, delivering speeches in eastern Cuba during a revolutionary holiday and making waves at a trade summit in Argentina. Those back-to-back trips and the resulting stress "ruined" his health, according to his letter.
"It's so surprising, because in Argentina he gave off such a strong political image and looked quite vital," said Rafael Marti, a businessman from Spain visiting Cuba with his wife. He said he didn't expect rapid change on the island 90 miles south of Florida.
Cubans agreed nothing was likely to change overnight -- especially not with Castro's fiercely loyal brother at the helm. Raul Castro, who turned 75 in June, has been his brother's constitutional successor for decades and has assumed a more public profile in recent weeks.
The calm delivery of the announcement appeared intended to signal that any transition of power would be orderly. Yet some feared resentment over class divisions could spark conflict if a political vacuum develops.
"It's better for things to move slowly, instead of abrupt change," Garcia said. "But people are a bit nervous -- anything could happen."
Dissidents said they expected the government to be on the defensive, with a high security presence and a low tolerance for political acts.
"It's clear that this is the start of the transition," said activist Manuel Cuesta Morua. "This gives Cuba the opportunity to have a more rational leadership" because top leaders will be forced to work together rather than following one man.
Officials halted some interviews by journalists Tuesday, with one plainclothes officer ejecting an Associated Press reporter from a cafe for asking questions. People on the street were reluctant to talk to foreign journalists, and many declined to give full names.
Several hundred government supporters gathered in Havana's Central Park to call for Castro's speedy recovery and voice support for Raul Castro.
"He's a great leader too," Francisco Urbay, 66, said of the younger brother.
Elsewhere, it looked like a regular day in Havana, with people packed into buses and standing in line outside stores.
In Washington, the State Department said it would support a democratic transition in Cuba. Spokesman Sean McCormack said the Cuban people are weary of communist rule and eager to choose a new form of government.
"We believe that the Cuban people aspire and thirst for democracy and that given the choice they would choose a democratic government," he said.
A Cuban fisherman said he had a message for the U.S. government: stay out.
"In my house, I don't allow any outsider to order me around," said Lazaro Alfonso Gonzalez, 58, at one of the government gatherings. "Cuba is my home, and none of us will allow anyone to come here and tell us what to do."
Castro, who took control of Cuba in 1959, has resisted repeated U.S. attempts to oust him as well as demands for multiparty elections and an open economy. He has survived communism's demise elsewhere and repeatedly insisted his socialist system would long outlive him.
Doctors in the United States said Castro's condition could be life-threatening but since the details of his symptoms were not released it was hard to say what caused the bleeding: severe ulcers, a colon condition called diverticulosis or -- an outside possibility -- cancer.
Castro seemed optimistic of recovery, asking in his letter that celebrations scheduled for his 80th birthday be postponed until Dec. 2, the 50th anniversary of Cuba's Revolutionary Armed Forces.
The leaders of China, Venezuela, Bolivia and Mexico wished Castro well.
Castro has been in power since the Jan. 1, 1959, triumph of the armed revolution that drove out dictator Fulgencio Batista. He has been the world's longest-ruling head of government, and his ironclad rule has ensured Cuba's place among the world's five remaining communist countries, along with China, Vietnam, Laos and North Korea.
Talk of Castro's mortality was taboo until June 23, 2001, when he fainted during a speech in the sun. Although Castro quickly recovered, many Cubans understood for the first time that their leader would eventually die.
Castro shattered a kneecap and broke an arm when he fell after a speech on Oct. 20, 2004, but laughed off rumors about his health, most recently a 2005 report he had Parkinson's disease.
Associated Press Writers Anita Snow and Andrea Rodriguez in Havana, Adrian Sainz in Miami, George Gedda in Washington, Ian James in Caracas, Venezuela, and Medical Writer Lindsey Tanner in Chicago contributed to this report.