Former U.S. President George H.W. Bush is recovering well from pneumonia but will remain in the intensive care unit at the Texas hospital where he has spent the last week, a spokesman said in a statement.

Barbara Bush, his wife, was also taken to the Houston Methodist Hospital this week with bronchitis but may be well enough to be discharged on Sunday, the statement said.

"Following another good night's rest, President and Mrs. Bush have both continued to improve over the past 24 hours," Jim McGrath, the spokesman, said in his statement.

"President Bush is breathing well without any mechanical assistance, his spirits are high, and he is looking forward to getting back to a regular schedule."

Bush, who at 92 is the nation's oldest living ex-president, was invited to attend Friday's inauguration of his fellow Republican Donald Trump as president. He ended up watching the proceedings from his hospital room and sent Trump, whom he did not endorse as a candidate, a letter of support, McGrath said.

He was the only living former president who did not attend the inauguration in Washington. His son George W. Bush, another former president, attended the ceremony.

Another one of his sons, former Florida Governor Jeb Bush, ran unsuccessfully against Trump last year for the Republican Party's presidential nomination.

The elder Bushes marked their 72nd wedding anniversary on Jan. 6.