Former US President George H W Bush has been in intensive care with a fever since Sunday, a spokesman has revealed.
"He's had a series of setbacks now that have landed him in
guarded condition in the intensive care unit," Jim McGrath said, quoted
by AFP. Mr Bush, aged 88, has been in the Methodist Hospital in Houston, Texas, since he was taken there for bronchitis treatment on 23 November.
He is the oldest living former president and a World War II veteran.
Mr Bush was now on a liquids-only diet, the spokesman said.
"His family was with him, and he's conscious and he's able to engage in humorous banter with his doctor," Mr McGrath said.
He also said that doctors were cautiously optimistic about Mr Bush's treatment.
Mr Bush was Ronald Reagan's vice-president for two terms and president for one, serving in the White House from 1989 until 1993.