(CNN) -- Venezuelan President Hugo Chavez is undergoing physical therapy in Cuba, an ally said Tuesday, a development that would be a significant step for the ailing leader if true.
"I have good news," Bolivian President Evo Morales said during his state of the union speech Tuesday, telling lawmakers that he had spoken to Cuban officials about Chavez on Sunday. "Our brother, president-commander Hugo Chavez, is already doing physical therapy to return to his country."
Later Tuesday, Venezuela's information minister said there was no date planned for Chavez to come back to Caracas, the capital.
"The news of the evolution of President Hugo Chavez's health has been encouraging, but there is no date set for his return," Ernesto Villegas said in televised remarks.
Venezuelan and Cuban authorities have been secretive about Chavez's health. The 58-year-old Venezuelan president has not made any public appearances since undergoing a fourth cancer surgery in Havana six weeks ago. The government has not released any photographs of the ailing leader, and Chavez hasn't spoken on state television.
The long absence from the airwaves is not typical of the loquacious leader. And his lengthy stay in Cuba has sparked growing concerns from political opponents about who's running Venezuela while he's gone.
On Monday, Chavez's brother released a statement saying the president's medical team would decide when he would come back to Venezuela.
"We all desire his return," Argenis Chavez said, denying reports that quoted him saying the president would return in the "coming days."
Morales' comment, along with another by Venezuela's foreign minister, paint an uplifting picture. But officials have previously provided rosy reports that did not pan out.
Chavez is awake, joking and, most importantly, still making decisions for the country, Foreign Minister Elias Jaua said.
Jaua said he met with Chavez on Monday in Cuba.
"Compatriots, leaving the meeting with our President Commander Hugo Chavez. We shared jokes and laughs," Jaua said in a tweet.
Jaua said Chavez was making decisions about the upcoming summit of the Community of Latin American and Caribbean States, a coalition of the region's countries.
"He made decisions about our participation in the Summit," the foreign minister tweeted. "Very happy that progress continues ..."
Two weeks ago, Chavez was unable to be sworn in for a new term because of his health.
The postponed inauguration raised constitutional questions about who was in charge of the country, opposition politicians have said. But the Supreme Court ruled that Chavez was still president and could be sworn in at a later date.
Behind the sometimes contradictory narratives coming from Cuba is the island nation's close relationship with Venezuela. Few countries have as much to lose as Cuba if cancer were to force Chavez from power.
Venezuela sends an estimated 100,000 barrels of oil a day to Cuba -- about two-thirds of the island's consumption -- at rates so favorable that no other country will match them, analysts said. In return, Cuba dispatches doctors and sports trainers to work in Venezuela.
Chavez's deputies have not said if they would continue the oil deal. Members of Venezuela's opposition have criticized the level of influence of the Cuban government over Venezuelan officials and have said the oil would be cut off if they took power.
"The impact of Cuba losing that arrangement would be disastrous," said Jorge Pinon, an oil expert at the University of Texas' Center for International Energy and Environmental Policy. "Cuba recently opened its gates for Cubans to be able to leave the island legally. If all of a sudden you have a major impact on the economy, the exit of Cubans from Cuba, I think, will be substantial, and I think most of them will probably go to Miami."
Many Cubans who remember the bleak economic times after Soviet aid dried up are worried that similar turmoil could be the result of Chavez's illness.
"We have received poetry, letters from children, from grandparents and have even had Cubans and foreigners who live here offering their lives if it would help improve our commander's health," said Edgardo Antonio Ramirez, Venezuela's ambassador to Cuba.
Cubans have held regular prayer services for Chavez. At a recent ceremony held by practitioners of the Afro-Caribbean religion Santeria, worshipers banged drums, smoked cigars and danced feverishly to scare away death.
The service, which usually is only held to cure Santeria followers, was attended by Venezuelan diplomats and military officials. In front of a large poster of Chavez, ceremony participants lit candles and made offerings.
"We are trying to give him all the spiritual energy we can," said Papo Angarica, the Santeria priest who officiated the service.
CNN's Rafael Romo, Mariano Castillo and Catherine E. Shoichet contributed to this report.