Cuban authorities have not commented on reports that President Fidel Castro, 80, is in serious condition.
The Spanish newspaper El Pais reported on its Web site Monday that the Cuban leader is in "very serious" condition after three failed operations and complications from an intestinal infection.
The paper said Mr. Castro suffers from a serious infection that has worsened to peritonitis, a painful and potentially fatal inflammation of the lining of the abdominal cavity. The report said he is being fed intravenously.
Cuba's official media has made no mention of the report.
A White House spokesman Tuesday called the report "nothing new."
A Spanish surgeon who examined Mr. Castro last month, Jose Luis Garcia Sabrido, told reporters in December the Cuban leader was slowly recovering and wanted to return to work. The surgeon denied reports the Cuban leader had cancer.
But El Pais cites sources at the surgeon's hospital as saying the infections have left Mr. Castro with "a very grave prognosis."
The Cuban leader underwent an operation at the end of July, and has not appeared in public since. He temporarily ceded power to his brother, Defense Minister Raul Castro.
The newspaper report has not been confirmed. The Cuban government treats Mr. Castro's health as a state secret.
Some information for this report was provided by AFP.