Venezuela plunged into political uncertainty Monday after the government announced that President Hugo Chavez had suffered a new setback after cancer surgery in Cuba and the situation he was facing was "tough."
"We have been informed of new complications that arose as a consequence of the respiratory infection we already knew about," Vice President Nicolas Maduro said Sunday in a TV and radio broadcast from Havana, where Chavez underwent his operation. Cuba is Chavez's closest regional ally.
"President Chavez's condition is still delicate," Maduro added, warning that the complications "are being treated in a process that is not without its risks."
Chavez, the face of the Latin American left for more than a decade and a firebrand critic of US "imperialism," has been in power since 1999 in Venezuela, an OPEC member that sits on top of the world's largest proven oil reserves.
Maduro, who said he had spoken with Chavez about his health complications and national affairs, added that the president was facing a "tough situation."
"Comandante Chavez particularly wanted us to relay his New Year's greetings to every Venezuelan family who are gathered together across the country at this time," Maduro said.
The vice president said he would stay in Havana in the coming hours with Chavez and his family to "closely" follow his progress.
"We trust that the global outpouring of love" for the Venezuelan leader will help him heal, said Maduro.
He was in Cuba with Rosa Virginia Chavez -- one of the president's daughters - Science and Technology Minister Jorge Arreaza and top Prosecutor Cilia Flores.
Chavez, 58, won another six-year term in October's presidential election, and is scheduled to be sworn in on January 10.
But his health has raised concerns over the future of his leftist movement - and whether he will even be well enough to attend his own inauguration.
Under Venezuela's constitution, a presidential election must be held within 30 days if the president is incapacitated or dies before his inauguration or within the first four years of his term.
Last Monday, the government had said there had been a "slight improvement" in his condition as he recovers from post-operative respiratory infection.
Officials have never disclosed the type or severity of Chavez's cancer, first diagnosed in June 2011, and he only designated a political successor - Maduro - earlier this month.
The longtime Venezuelan leader had, in fact, asserted before embarking on his arduous re-election campaign earlier this year that he was cancer-free.
But he was later forced to admit he had suffered a relapse.
In an announcement made in Caracas before his departure, Maduro did not specify how long the group would stay in Havana. But he said Electricity Minister Hector Navarro would assume the vice presidency during his absence.
Since Chavez headed to Cuba on December 10 for a fourth round of surgery since he was diagnosed with cancer in 2011, Maduro has worked on honing his skills as a higher-profile leader in his own right.
Maduro, 50, a former bus driver and transport union activist, has lashed out at the opposition, Chavez-style, on national television.
And he has combatively pledged to fight to defend the socialist revolution that Chavez, a leftist ex-paratrooper, launched.
Maduro has played a prominent role at swearing-in ceremonies, and in speeches has "taken on the tone of someone who is on the campaign trail," said DataStrategia chief Carmen Beatriz Fernandez.
"He has been anointed as Chavez's heir, and now he is taking up that role actively. He is preparing himself for a presidential election in the near future," she said last week.
"Maduro used to look much more moderate, calmer, but now he seems to be imitating Chavez's role, and trying to be more belligerent," Fernandez said.