David Jackson

USA TODAY

Former president George H.W. Bush is in the intensive care unit for "an acute respiratory problem stemming from pneumonia," a family spokesman said Thursday.

Former first lady Barbara Bush is also in Houston Methodist Hospital "as a precaution after experiencing fatigue and coughing," spokesman Jim McGrath said.

The former president, age 92, went into the hospital over the weekend for shortness of breath.

"Doctors performed a procedure to protect and clear his airway that required sedation," McGrath said. "President Bush is stable and resting comfortably in the ICU, where he will remain for observation."

Neither of the Bushes will be able to attend Friday's inauguration of Donald Trump.

In a letter to the president-elect, Bush wrote: "My doctor says if I sit outside in January, it likely will put me six feet under. Same for Barbara. So I guess we’re stuck in Texas.”

During his news conference Wednesday, President Obama sent his prayers to George H.W. and Barbara Bush, saying they have been "a constant source of friendship and support and good counsel" to him and first lady Michelle Obama.

"They are as fine a couple as we know," Obama said of the Bushes. "Really good people."

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George H.W. Bush and Barbara Bush hospitalized