Cuba's vice president and Venezuela's leader provided optimistic assessments of Fidel Castro's health, saying the Cuban president was recovering quickly from intestinal surgery and could be back at work within weeks. Castro himself has been out of sight since July 31, when his secretary went on state television to announce he had undergone surgery and was temporarily ceding power to his younger brother, Defense Minister Raul Castro. "In a few weeks he'll be recovered and he'll return to his duties," Vice President Carlos Lage said Sunday when asked by reporters when Castro would be back at work. Lage spoke in Bolivia, where he attended the Andean country's constitutional convention. Cubans were told most details of Castro's health would be kept "a state secret" to prevent the island's enemies from taking advantage of his condition. Indeed, officials have failed to say what precisely is ailing Castro or what surgical procedure he underwent. Lage had earlier shot down reports that Castro, who turns 80 next Sunday, had stomach cancer and reiterated Sunday that the Cuban leader was recovering well. "The operation that he underwent was successful and he is recovering favorably," Lage said. "Fidel's going to be around for another 80 years." Meanwhile, Venezuelan President Hugo Chavez said Castro was out of bed and talking following his surgery. "How are you, Fidel?" Chavez said during his weekly TV and radio program, suggesting he believed the Cuban leader was watching. "We have reliable information of your quick and notable recuperation." "Fidel Castro, a hug for you, friend and comrade, and I know you are getting better," Chavez said. Talking by phone with Bolivian President Evo Morales later during the program, Chavez said that Castro was bouncing back quickly. "This morning I learned that he's very well, that he is already getting out of bed, he's talking more than he should - because he talks a lot, you know. He has sent us greetings," Chavez said. Morales, a leftist elected in December as Bolivia's first Indian president, said he was glad to learn of Castro's recovery and that "what's left is for him to be incorporated into the battle of his country" again. Morales said Castro was like an "older brother." Before Castro fell ill, Morales had promised to travel to Havana for Castro's birthday and bring him a cake made from the flour of coca leaves. The Bolivian leader said his government would send a high-level mission to Havana in the coming days, according to his spokesman Alex Contreras. Malaysia's prime minister on Monday wished Castro a swift recovery and said he looks forward to seeing him at a summit in Havana next month. "I am pleased to hear your operation has been successful and that you are responding well to medical treatment," Prime Minister Abdullah Ahmad Badawi said in a statement carried by Malaysia's national news agency, Bernama, from the capital of Kuala Lumpur. Abdullah said he hopes to meet with Castro during a meeting of leaders of mainly developing countries of the Nonaligned Movement that Cuba is hosting September 11-16. Malaysia has held the rotating chairmanship of the 116-member Nonaligned Movement since 2003, and is to hand over the reins to Cuba next month. From Managua, former Sandinista rebel commander Tomas Borge praised Castro's choice of Raul as "the most suitable person" for provisional president, Cuba's Prensa Latina news agency said. Borge, a Nicaraguan parliament deputy with the Sandinista Party, told Prensa Latina Castro once told him that his younger brother was the best organizer he knew. Raul's absence from the spotlight after being named interim president was "a demonstration of humility and of profound respect toward the leader of the revolution," Borge added. Former Nicaraguan President and Sandinista revolution leader Daniel Ortega arrived in Havana from Nicaragua late Saturday. "I am sure that we will soon have Fidel resuming his functions and leading his people," Ortega said. As get-well wishes poured in from leftists across the hemisphere, even Colombia's largest rebel group expressed its solidarity with the ailing Cuban leader. "We hope you'll recover in the shortest time possible," read a statement from the leftist Revolutionary Armed Forces of Colombia. In Washington, Secretary of State Condoleezza Rice said Sunday the United States wants to help Cubans prepare for democracy but is not contemplating an invasion of the island in the wake of Castro's illness. "The notion that somehow the United States is going to invade Cuba, because there are troubles in Cuba, is simply far-fetched," Rice told NBC television. "The United States wants to be a partner and a friend to the Cuban people as they move through this period of difficulty and as they move ahead. But what Cuba should not have is the replacement of one dictator by another." Cuban authorities have beefed up security by mobilizing citizen defense militias, increasing street patrols, and ordering decommissioned military officers to check in at posts daily.