(Reuters) - Former President George H.W. Bush's breathing has returned to normal and he is awaiting doctors' approval to be discharged from a Houston hospital where he has been receiving treatment for nearly a week, his office said on Monday.

"He will remain at the Houston Methodist Hospital tonight pending final approval from his doctors to return home," said Jim McGrath, a spokesman for the 90-year-old former Republican president.

Bush was taken by ambulance to Houston Methodist Hospital last Tuesday night and admitted for observation after experiencing breathing difficulties, according to the spokesman for the 41st U.S. president.

McGrath said over the weekend that doctors "have begun discussing dates for his discharge."

Bush, who was president from 1989 to 1993, was admitted to the same hospital in November 2012 for treatment of bronchitis and related ailments. He was so ill at one point that he was believed to be near death, but he recovered and was allowed to go home after seven weeks.

Bush suffers from Parkinson's disease and cannot use his legs. But he celebrated his 90th birthday on June 12 by skydiving near Kennebunkport, Maine, with the Army's Golden Knight parachute team.

His eldest son, former President George W. Bush, published a best-selling book this year about his father, titled "41 - A Portrait of My Father."