Venezuela's President, Hugo Chavez, is suffering from "complications" brought on by a "severe lung infection" which developed after surgery, officials say.
Mr Chavez, 58, had his fourth operation for cancer in Cuba on 11 December and then developed a respiratory infection.
In a statement from Caracas, Information Minister Ernesto Villegas said the infection had "led to a respiratory insufficiency".
Mr Chavez is due to be sworn in for another term in office on 10 January.
"[Mr] Chavez has faced complications as a consequence of a severe lung infection," said Mr Villegas.