Pope Francis was hospitalized with a respiratory infection Wednesday after experiencing difficulty breathing in recent days and will remain in the Rome hospital for several days of treatment, the Vatican said.

The 86-year-old pope, who had part of one lung removed as a young man, doesn't have COVID-19, spokesman Matteo Bruni said in a statement late Wednesday.

The hospitalization was the first since Francis spent 10 days at the Gemelli hospital in July 2021 to have 33 centimeters (13 inches) of his colon removed.

It immediately raised questions about Francis' overall health, and his ability to celebrate the busy Holy Week events that are due to begin this weekend with Palm Sunday.

Bruni said Francis had had trouble breathing in recent days and went to the Gemelli hospital Wednesday for tests.

“The tests showed a respiratory infection (COVID-19 infection excluded) that will require some days of medical treatment in the hospital,” Bruni's statement said.

Francis appeared in relatively good form during his regularly scheduled general audience earlier Wednesday, though he grimaced strongly while getting in and out of the “popemobile.” He nevertheless rode around the square as usual, kissing babies and greeting the faithful.

Bruni said Francis, an Argentine Jesuit, was grateful for the prayers and messages wishing him a speedy recovery, including from the Italian bishops conference.

President Joe Biden, at the start of an Oval Office meeting with President Alberto Fernández of Argentina, told reporters he had just learned of Francis’s health problems and said he was concerned about his dear “friend.”

Francis had part of one lung removed when he was a young man due to a respiratory infection, and he often speaks in a whisper. But he got through the worst phases of the COVID-19 pandemic without at least any public word of ever testing positive.

Francis was scheduled to celebrate Palm Sunday this weekend, kicking off the Vatican's Holy Week observances: Holy Thursday, Good Friday, the Easter Vigil and finally Easter Sunday on April 9. He has canceled all audiences through Friday, but it wasn't clear whether he could keep the Holy Week plans.

Francis has used a wheelchair for over a year due to strained ligaments in his right knee and a small knee fracture. He has said the injury was healing and been walking more with a cane of late.

Francis also has said he resisted having surgery for the knee problems because he didn't respond well to general anesthesia during the 2021 intestinal surgery.

He said soon after the surgery that he had recovered fully and could eat normally. But in a Jan. 24 interview with The Associated Press, Francis said his diverticulosis, or bulges in the intestinal wall, had “returned."