President Hugo Chavez died of a massive heart attack after great suffering and inaudibly mouthed his desire to live, the head of Venezuela's presidential guard said late Wednesday.

"He couldn't speak, but he said it with his lips ... 'I don't want to die. Please don't let me die,' because he loved his country, he sacrificed himself for his country," General Jose Ornella said.

The general said he spent the last two years with Chavez, including his final moments, as Venezuela's president of 14 years battled an unspecified cancer in the pelvic region.

He said Chavez's cancer was very advanced when death came but gave no details. Ornella did not respond when asked if the cancer had spread to Chavez's lungs.

The government said on the eve of Chavez's death that he had suffered a severe new respiratory infection. It was the second respiratory infection reported by officials after Chavez underwent his fourth cancer surgery in Cuba on December 11.

Venezuelan authorities have not said what kind of cancer Chavez had or specified exactly where tumours were removed.