Venezuela’s Vice President and acting leader Nicolas Maduro has warned the nation of a tough road ahead, saying President Hugo Chavez faced a difficult recovery from cancer surgery.

As of Wednesday night, Chavez was in stable condition, Information Minister Ernesto Villegas said in a radio and TV broadcast.

But his six-hour operation on Tuesday “was complex, difficult, delicate, which tells us that the post-surgery process will also be complex and difficult,” Maduro, Chavez’s handpicked successor, said hours earlier.

The President “was very clear” that the country must be “prepared to face a tough and difficult situation” that can be overcome only if Venezuelans remain “united,” said Maduro, who was flanked by senior government officials.

In one flash of confidence he did say: “Sooner rather than later, we will have our comandante here,” but he gave no indication of when Chavez might return to Venezuela following Tuesday’s fourth round of cancer surgery.

The type, location and severity of Chavez’s cancer have been kept secret over the past 18 months, fueling rumours and uncertainty in Venezuela.

Chavez flew to Havana for surgery on Monday after revealing that his cancer had returned just two months after his triumphant re-election to a new six-year term that begins on January 10.

The 58-year-old President was first diagnosed with the disease in June 2011. After three rounds of surgery, in addition to chemotherapy and radiation, Chavez had assured Venezuelans earlier this year that he was cancer-free.

The operation “ended correctly and successfully,” Maduro, to whom Chavez delegated power before flying to Havana, had told Venezuelans late on Tuesday. The vice president described the procedure as a “corrective surgery of a lesion” that occurred in the pelvic region, but did not elaborate.

Without formally handing over the presidency, Chavez said he was delegating the country’s “high political command” to Maduro, 50, and said the vice president would succeed him if he became incapacitated. Under Venezuela’s constitution, elections must be held within 30 days if the president dies or is incapacitated.

Chavez supporters held religious services and candlelight vigils across the country, praying for their leader to overcome the disease.