Venezuela's Vice-President Nicolas Maduro talks to the media during a visit to Fama de America's coffee processing plant in Caracas Jan 3, 2013. Maduro returned to Venezuela on Thursday after visiting Hugo Chavez in hospital in Cuba, but gave no new details on the cancer-stricken president as rumors grow about his condition.[Photo/Agencies]

CARACAS - Venezuelan President Hugo Chavez is still suffering from a "severe" lung infection that has caused breathing difficulties as he struggles to recover from a Dec 11 cancer surgery in Cuba, officials said on Thursday.

"Commander Chavez has faced complications as a result of a severe lung infection," Information Minister Ernesto Villegas said in a national broadcast.

"This infection has caused a respiratory insufficiency that requires Commander Chavez to strictly comply with medical treatment," Villegas said, giving no further details.

There have been shifting rumors about Chavez's health condition, which could bar him from being sworn in to his third six-year term on Jan 10. Chavez won the October presidential election with a 55-percent majority.

On Wednesday, his son-in-law Jorge Arreaza said on Twitter that Chavez's medical team has said his condition "continues to be stable, but delicate."

The Venezuelan president has been fighting an undisclosed type of pelvic cancer since June 2011 and underwent a fourth round of surgery in Cuba on Dec 11.

Vice-President Nicolas Maduro, to whom Chavez last month transferred some of his power during his illness, has called on Venezuelans to ignore the rumors about Chavez's health, saying they were being spread due to "the evil and the hatred of the enemies of Venezuela."

According to the Venezuelan Constitution, an early presidential election will be called within 30 days should Chavez be unable to return to power.