Fourth operation

Chavez's arrival implied some improvement in his condition, at least enough to handle a flight of several hours.

But there was no new information on his precise condition, and aides have emphasized in recent days his state remains delicate. "It's a complex, difficult situation, but Chavez is battling ... fighting for his life," Foreign Minister Elias Jaua said over the weekend, describing a recent visit to Chavez.

A supporter of Venezuela's President Hugo Chavez cheers outside the military hospital after his surprise return to Caracas Feb 18, 2013. [Photo/Agencies]

The December operation in Havana was his fourth for the cancer first detected in his pelvic area in June 2011.

On Friday, the government published photos showing him lying in hospital. Officials said he was breathing through a tracheal tube and struggling to speak.

Chavez's return was a typical surprise move for the former soldier whose political rule has combined constant theatrics with thundering anti-US rhetoric.

Opponents have been decrying government secrecy over Chavez's condition, and some have called for a formal declaration that he is unfit to rule. That scenario would trigger a new presidential election within 30 days, probably between Maduro and opposition leader Henrique Capriles.

After winning re-election in October last year, and wrongly declaring himself cured, Chavez was unable to attend his own swearing-in ceremony in January. To the fury of his foes, Venezuela's Supreme Court ruled that he remained president and could be sworn in at a later date.

That could now happen at the military hospital.

"Now the president is back, there can be no doubt about the democratic institutions working in Venezuela," Information Minister Ernesto Villegas said.

"There were some who dream of unseating Chavez and the revolution, but here we always said Chavez is the president elected and re-elected by will of the Venezuelan people."

Reuters-AP