Citing unnamed hospital sources in Havana, where Chavez has been undergoing treatment, the ABC report said that Chavez could pass away at any time.
However, ABC doesn't have an entirely solid record of reporting on Cuba, according to GlobalPost's correspondent there. The Venezuelan government, meanwhile, has disputed reports that Chavez is near death.
Venezuela Vice President Nicolas Maduro, insisted in a televised interview Tuesday that Chavez was conscious, though he acknowledged the president's situation following surgery for cancer was "complex and delicate."
Chavez "asked us expressly" to give the people of Venezuela "the truth" about his health, even if the news isn't good, Maduro told a TeleSUR interviewer. He also asked the people to have faith that the government will keep them informed.
Opposition politicians have accused the Venezuelan government of withholding information about the leader's health, questioning whether Chavez could realistically return home to be sworn into a new term in office on Jan. 10. On Wednesday, they called on the adminstration to give answers, according to the Los Angeles Times.
"To make us believe the president is governing shows a lack of seriousness that borders on irresponsibility," opposition leader Ramon Guillermo Aveledo told reporters in Caracas, according to the LA Times.
The ABC report said a team of mostly Russian doctors operated on Chavez in Havana on Dec. 11, 2012 to stop the aggressive spread of cancer through his pelvic region.
The report further claimed Chavez's cancer has since crept into his lower spine, bladder and other organs, while a respiratory infection has left Chavez breathing through a tracheotomy and eating through a tube.
But GlobalPost's Nick Miroff said the truth about Chavez's current state is unclear.
"His true condition is a Venezuelan state secret, so until the state gives more information, we probably won't really know how Chavez is doing or if any of this stuff is true," he wrote.
Miroff was also skeptical about the source of the report.
"The right-leaning ABC hasn't been a particularly reliable source of information from Cuba in the past," he wrote. For example, previous ABC reports on the "imminent demise" of Fidel Castro have been inaccurate, Miroff said. "Still, no one doubts Chavez's health is precarious, as Venezuelan officials acknowledge," he added.
Venezuelan officials said Sunday that Chavez was suffering complications from a respiratory infection. But they have given conflicting indications about the extent of the president's illness, the Guardian reported. On Tuesday, Vice President Maduro described Chavez as possessing "the same strength as always."
In the same interview, Maduro blamed "right-wing" journalists against the regime for spreading rumors that Chavez is near death.