TULCAN: Venezuelan President Hugo Chavez was in surgery on Tuesday in Havana to treat a return of his cancer, Ecuador’s President Rafael Correa said, after visiting his close ally in Cuba.

Chavez is being subjected “at this instant to a very delicate operation,” Correa said in opening a meeting with Colombian President Juan Manuel Santos in the border city of Tulcan, 150 kilometres north of Quito.

“My dear friend and colleague, Commander Hugo Chavez, is going through the toughest times of his life,” Correa said in Ecuador.

Correa said earlier in the day that Chavez was in good spirits as he awaited another round of cancer surgery.

“Chavez in great spirits. He gives us all strength,” Correa said on his Twitter account after flying back to Quito.

Venezuelans were waiting for news of Chavez’s surgery, his latest bout of ill health that has thrown his future into jeopardy and upended politics in the South American OPEC nation.

The long-serving president has returned to politically allied Cuba for a fourth operation since mid-2011, after cancer was again discovered in the pelvic area soon after he won re-election in October.

Chavez’s ministers have been parading on state TV to pledge loyalty to their boss but have given no details of his condition, which is treated virtually as a state secret.

Having declared himself “completely cured” twice in the past, the president has acknowledged he may be incapacitated, though he said he still hopes to recover in time to start his new, six-year term on Jan.10.

Chavez has named vice president and foreign minister Nicolas Maduro as a potential successor to lead his self-styled revolution in the South American nation of 29 million people that has the world’s largest oil reserves.

Maduro, 50, a former bus driver and union activist, lacks his boss’s charisma and political flair but would represent policy continuity should he formally take over.

He has already taken control of day-to-day government operations.

The naming of Maduro has irked some in Venezuela’s opposition, who say voters — not Chavez — will decide who follows him if an election is held within 30 days of his leaving office — as mandated by the constitution.