Francis, who spoke to journalists and members of the media as he departed the hospital Saturday morning, will be at St Peter's Square for Palm Sunday Mass to mark the start of Holy Week.

Pope Francis on Saturday joked that he is "still alive" as he left a hospital in Rome where he spent three days being treated for a respiratory infection.

Francis was taken to Gemelli hospital on Wednesday with breathing difficulties and was given antibiotics for the treatment of infectious bronchitis after being diagnosed with it.

The Vatican said earlier Friday that the 86-year-old Pope would be released Saturday morning if his latest test results allowed it.

Francis, who spoke to journalists and members of the media as he departed the hospital Saturday morning, embraced a couple whose daughter had died Friday night at the hospital and signed a boy's cast before leaving the site.

"I wasn't frightened, I'm still alive," he told reporters outside the hospital in a light-hearted remark before being driven away in a white Fiat 500.

He was seen smiling and waving from the car, before getting out to speak to a crowd. He then headed for the Vatican.

The Vatican confirmed the Argentine pontiff will be at St Peter's Square to participate in a Palm Sunday Mass service to mark the start of Holy Week.

Holy Week, as it is known, includes a busy schedule of events and services that can be physically demanding.

Francis, who marked 10 years as head of the Catholic Church earlier this month, has suffered a number of health issues throughout his life.

As a young man, he suffered from severe pneumonia and had part of one of his lungs removed at the age of 21. He has often been seen with a walking stick and sometimes uses a wheelchair due to pain in his right knee. 

Francis also suffers from diverticulitis, a common condition that can cause the inflammation or infection of the colon. In 2021, he had surgery to remove part of his colon.