VATICAN CITY (AP) — Pope Francis on Sunday asked for prayers to accompany him on what he called his “penitential” pilgrimage to Canada to apologize to Indigenous groups for abuses inflicted by the Catholic church.

Greeting the public in St. Peter’s Square, Francis noted that on July 24, “God willing,” he will begin a seven-day trip to Canada.

“Dear brothers and sisters of Canada, as you know I will come among you above all in the name of Jesus to meet and embrace the Indigenous populations,” Francis said.

“Unfortunately, in Canada, many Christians, including some members of religious institutions, contributed to the policies of cultural assimilation, that, in the past, gravely damaged, in various ways, the Native communities,” the pope said, speaking from a studio window of the Apostolic Palace facing the square.

“For this reason, recently, at the Vatican, I received several groups, representatives of Indigenous peoples, to whom I manifested by sorrow and my solidarity for the evil they have suffered,” Francis said.

“And now I will make a penitential voyage that I hope, with the grace of God, can contribute to the path of healing and reconciliation already undertaken,” said Francis, appealing for the faithful to “accompany me with prayers” during the pilgrimage.

When he met with Indigenous representatives in early spring, the pontiff offered an historic apology for the abuses inflicted at church-run residential schools. Canada’s Truth and Reconciliation Commission called for him to deliver a papal apology on Canadian soil.

More than 150,000 native children in Canada were forced to attend state-funded Christian schools from the 19th century until the 1970s in an effort to isolate them from their homes and culture. The aim was to Christianize and assimilate them into mainstream society, which previous Canadian governments considered superior.

The Canadian government has admitted that physical and sexual abuse was rampant at the schools, and that students were beaten for speaking their native languages. Indigenous leaders say the legacy of abuse and family separation was a root cause of the epidemic rates of alcohol and drug addiction on Canadian reservations.