Pope Francis departs Sunday for a historic six-day visit to Canada where he is expected to ask forgiveness of Indigenous survivors of abuse committed at residential schools run by the Catholic Church.

The "penitential pilgrimage", as the pontiff has described it, is seen as an important step in addressing the global scandal of clerical sexual abuse of children and decades of cover-up.

It has long been awaited by Canada's Indigenous communities.

Pope Francis will begin his 37th international trip since becoming pontiff in Edmonton, in the western province of Alberta, before heading to Quebec City and then Iqaluit, Canada's northernmost city.

This is the 37th international trip Pope Francis is making since he became pontiff
This is the 37th international trip Pope Francis is making since he became pontiff AFP / Filippo MONTEFORTE

He plans to reiterate an apology delivered to Canadian delegations who visited the Vatican in April, which he then said would hopefully "contribute to the journey of healing and reconciliation already undertaken".

The discovery since last year of hundreds of remains of Indigenous children in unmarked graves on the site of state schools administered by the Catholic Church has forced Canada to confront its failed policy of forced assimilation.

It has similarly shone a spotlight on the Church's role in what a national truth and reconciliation commission has called "cultural genocide".

Around 150,000 First Nations, Metis and Inuit children were enrolled from the late 1800s to the 1990s in 139 residential schools, where they spent months or years isolated from their families, language and culture.

Many were physically and sexually abused by headmasters and teachers.

Francis plans to reiterate an apology delivered to Canadian Indigenous groups who visited the Vatican in April
Francis plans to reiterate an apology delivered to Canadian Indigenous groups who visited the Vatican in April VATICAN MEDIA via AFP / Handout

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 sites of the former schools.

Francis kicks off the trip Monday with a stop in the town of Maskwacis, about 100 kilometres (160 miles) south of Edmonton, home to one of the largest of Canada's residential schools.

Hundreds of Indigenous children have been found in unmarked graves on the sites of state residential schools administered by the Catholic Church.
Hundreds of Indigenous children have been found in unmarked graves on the sites of state residential schools administered by the Catholic Church. AFP / Cole Burston

He will address an expected crowd of about 15,000 people, including former students from across Canada.

Although some have expressed enthusiasm over the pope's willingness to meet them, others are asking whether the short visit can heal wounds.

"A lot of people are going to be disappointed in the time that's given to them because it's years and years of trauma," said the chief of the Ermineskin Cree Nation, Randy Ermineskin, during a press conference held last month.

"Because he will apologise then he leaves and you're left holding the bag. Who's gonna look after these individuals?"

On Tuesday, the spiritual leader of the world's 1.3 billion Catholics will celebrate Mass at a 60,000-seat stadium in Edmonton before heading northwest to Lac Sainte Anne, the site of a major annual pilgrimage.

He then travels to Quebec City where he will meet Prime Minister Justin Trudeau and celebrate Mass at the Basilica of Sainte-Anne-de-Beaupre, a national shrine that draws over one million pilgrims each year.

On Friday, the pontiff will go to Iqaluit, home to the largest number of Inuit people in the country, where he will meet with former residential school students, before returning to Rome.

It remains to be seen whether, in a gesture of goodwill, the pope returns Indigenous artefacts currently held by the Vatican Museums.

Indigenous groups say these culturally valuable objects should be repatriated back to their communities despite the Vatican's assertions that they were given as gifts to popes in years past.

During his trip, Francis will travel 20,000 kilometres despite suffering from pain in his right knee that has forced him in recent months to rely on a cane or wheelchair.

In June, the Vatican postponed indefinitely a visit to Africa that had been scheduled for July.

Francis is the second pope to visit Canada, after John Paul II who visited three times (1984, 1987 and 2002).