Venezuela's government says President Hugo Chavez is facing complications from a severe lung infection.
Information Minister Ernesto Villegas said Thursday that the lung infection has caused a "breathing insufficiency" that requires Chavez to strictly comply with medical treatment. He gave no further details.
The Venezuelan leader has not been seen in public since undergoing cancer surgery in Cuba on December 11. He was first diagnosed with cancer in 2011, but has never disclosed the type or severity.
Earlier this week, Vice President Nicolas Maduro described Chavez's condition as "delicate."
Venezuelan opposition leaders have been demanding more information about the president's condition.
He is scheduled to sworn in for a new six-year term on January 10, after defeating opposition leader Henrique Capriles in October polling.
Venezuela's constitution stipulates if the president dies or is declared incapacitated, a new election must be held within 30 days.
Villegas condemned international media reports on Chavez, saying the media was waging a "psychological war" aimed at destabilizing the country.