Pope Francis will make a highly sensitive visit to Canada as planned next month, the Vatican confirmed Thursday, despite problems with his knee that caused him to postpone a trip to Africa.

The programme was released for the July 24-30 visit to Edmonton, Quebec and Iqaluit, where the pontiff will meet with Indigenous survivors of abuse committed at schools run by the Catholic Church.

The 85-year-old has cancelled numerous events in recent months due to pain in his knee that has forced him to use a wheelchair at official events, prompting intense speculation about his health - and his future.

However, the trip to Canada is an important step in his efforts to address the global scandal over sexual abuse of children by clergy and decades of cover-up.

He is expected to repeat an apology he delivered to Canadian delegations who visited the Vatican in April.

Some 150,000 First Nations, Metis and Inuit children were enrolled from the late 1800s to the 1990s in 139 residential schools across Canada, as part of a government policy of forced assimilation.

They spent months or years isolated from their families, language and culture, and many were physically and sexually abused by headmasters and teachers.

Thousands are believed to have died of disease, malnutrition or neglect. More than 1,300 unmarked graves have been discovered since May 2021 at the schools.

On June 10, the Vatican postponed a trip scheduled for early July to South Sudan and the Democratic Republic of Congo "at the request of his doctors", to avoid jeopardising therapy on the pope's knee.

A scheduled trip to Lebanon in June was also postponed due to health reasons, according to that country's government - although the Vatican had never confirmed the visit.

The news sparked fresh speculation about the future of Francis, who was elected pope in 2013 after his predecessor Benedict XVI resigned, citing his declining mental and physical health.