BOGOTA -- Venezuelan President Hugo Chávez is likely to face a “complex and difficult” recovery after undergoing surgery in Cuba for recurring cancer, Vice President Nicolás Maduro told the nation Wednesday, casting doubt on the 58-year-old leader’s ability to take office Jan. 10.

In a televised address, a somber-looking Maduro said the surgery had been “complex, difficult [and] delicate,” but that Chávez was in the process of recovering.

“We trust that with the help of God we are going to be victorious,” he said. “And that sooner rather than later we will have our president here.”

The administration did not say when Chávez would return to Venezuela, or whether he will be ready to begin a new six-year term next month, but Minister of Information Ernesto Villegas said the nation needs to be prepared for all eventualities.

“We trust that, with the love of millions, the Commander will respond quickly and return before January 10,” Villegas wrote on the ministry’s website. “But if not, the nation needs to be prepared to understand it. It would be irresponsible to cover up how delicate the situation is now and will be in the days to come.”

Chávez traveled to Cuba early Monday to undergo a fourth round of surgery to treat an undisclosed form of cancer he has been battling since at least June 2011. Before leaving, Chávez anointed Maduro his political successor and asked the nation to rally behind the former union leader who has strong ties to Cuba.

If Chávez were unable to take office, or be incapacitated within the first four years of his new term, it would trigger snap elections.

Flanked by National Assembly President Diosdado Cabello and Oil Minister Rafael Ramírez, Maduro said he would keep the nation “accurately informed and prepared” about Chávez’s recovery.

But he also called on detractors to quit “speculating” and “lying” about the president’s condition.

“Stop with your hate against President Chávez. Stop with your vicious attacks,” he said.

Social networks and websites have been in overdrive for weeks with theories about Chávez’s health. The rumors have found traction, because the administration has never said what type of cancer he has or what organs are being affected.

In power since 1999, the socialist firebrand has survived four elections, a recall attempt and one coup. Since announcing that doctors had removed a baseball-sized tumor from his pelvis last year, he has undergone chemotherapy and radiation treatment, but always bounced back. Many of his supporters in the oil-rich nation say they cannot imagine Venezuela without their charismatic leader.

On Wednesday, Villegas tried to put the situation in context.

“The president is a human being,” Villegas wrote. “This is like having a sick father in a very delicate situation after undergoing four surgeries in a year and a half.”

The news comes as Chávez’s PSUV party is hoping to sweep Sunday’s regional elections to choose 23 governors.

Despite worries that the vote might be delayed or cancelled, Maduro said everything was in order.

“We hope that Sunday’s elections will be a festival of participation,” he said. “That’s what our commander Chávez wants.”