Pope Francis will spend the next week on a “pilgrimage of penance” in Canada, meeting with Indigenous leaders and residential school survivors as he looks to atone for the church’s grim legacy in the country.

For the first papal visit to Canada in two decades, the pontiff plans to visit First Nations, Métis and Inuit communities as he travels from Alberta to Quebec, ending his visit in the Arctic territory of Nunavut.

While the head of the Catholic church will deliver public masses and meet state officials and supporters, much of his trip – named Walking Together – is expected to centre on reconciliation and recognition of the harms of the church-run residential school system in Canada.

Over more than a century, at least 150,000 Indigenous children were taken from their families and forced to attend the schools, many of which were run by the Catholic church.

Last year, ground-penetrating radar confirmed what Indigenous communities had long suspected, that more than 1,000 possible unmarked graves were hidden on the grounds of dozens of schools across the country.

In April, during a meeting with Indigenous delegates at the Vatican, Pope Francis apologised to survivors, formally expressing contrition for “deplorable” past abuses.

Indigenous leaders have expressed cautious optimism that the visit will refocus attention on the harms of the residential school system – and the challenges of reconciliation.

Francis is expected to issue his first papal apology when he visits the former Ermineskin Indian residential school in Maskwacis, Alberta on Sunday. The school was one of the largest in Canada, operating from 1916 until 1975.

Despite the church’s shift towards atonement in recent years, its handling of financial settlements are likely to once again come under scrutiny.

As part of a 2007 agreement, the Catholic church agreed to pay C$29m in compensation to survivors, but distributed only a fraction of that figure, citing poor fundraising efforts. But reporting by Canadian media outlets revealed the church controls more than C$4bn in assets and constructed gilded cathedrals while claiming it lacked the funds to honour its promise of compensation. Indigenous leaders have also called for all of the school records to be released unredacted.

Victims of abuse, many of whom are languishing through the courts in the pursuit of justice, have written to the pope through their lawyers, asking him to direct dioceses and congregations to assist investigators and police. During a private meeting with the pope in April, the leader of Canada’s largest Inuit organisation called on the pope to speed up efforts to have a “devil priest” extradited and arrested.

Senior figures within the church in Canada have already expressed regret and dismay at the harmful legacy of the schools. But the symbolic nature of pope’s visit to issue an apology has prompted some groups to call for other actions.

The Dehcho First Nations in the Northwest Territories want the Vatican and the federal government to renounce the “doctrine of discovery” – a papal decree that paved the way for settlement of North America by Europeans.

“It is important to remember that the colonial assault on our nations and cultures was justified and legitimised by the so-called ‘doctrine of discovery’, which falsely claimed that our nations were not already governing the lands and waters of Turtle Island long before Europeans arrived,” the nations said in a statement.

While the Canadian Conference of Catholic Bishops previously rejected the decree in 2015, leaders want a renouncement of the papal bull to come from the church’s highest figure.

With the expectation that Pope Francis will apologise for the harms caused by church on the ground where those abuses happened, groups that work with survivors have spent months preparing cultural support unique to different nations.

“We have to plan for every possible scenario – even the ones that we don’t even anticipate, so that people feel safe,” said Angela White, the executive director of the Indian Residential Schools Survivors Society.