Former President George H.W. Bush moved to intensive care unit - UPDATED

Former President George H.W. Bush’s condition has worsened and the 88-year-old has been moved to the intensive care unit at the Houston hospital where he is being treated.

Bush’s spokesman, Jim McGrath, sent an email to the media late Wednesday, announcing that the oldest living president has suffered “a series of setbacks,” which includes a stubborn fever. McGrath confirmed that Bush was moved to the ICU at Methodist Hospital on Sunday, reports The Associated Press.

His doctors continue to be “cautiously optimistic” and that Bush “remains in guarded condition.” His family is with him.

According to Reuters, a hospital spokesman did say earlier this month that Bush could be home for Christmas, but doctors decided that it would be better for him to remain at the hospital to build up his strength.

McGrath told the AP Thursday that another statement will be released “when events warrant it.”

Bush was hospitalized last month for “complications related to his bronchitis,” his office said at the time. He was diagnosed with lower body parkinsonism earlier this year and has had to use a wheelchair.

Bush was the 41st President and served one term before losing to Bill Clinton. He was also President Ronald Reagan’s Vice President during Reagan's two terms in office. Bush also served as a naval aviator in World War II. His sons, former President George W. Bush and former Florida Gov. Jeb Bush have visited him in the hospital.

UPDATED: McGrath told the Houston Chronicle that Bush "is considered in guarded condition...He has suffered a series of setbacks." The former president is alert and with family and is still being treated for a persistent fever.