Pope Francis on Friday made his first public plea for forgiveness for the "evil" committed by priests who molested children, using some of his strongest words yet on the Roman Catholic Church's crisis over sexual abuse.

The Argentine-born pontiff said the church, which last month named a high-level group on the scandal, including an abuse victim, has to take an stronger stand on a scandal that has haunted it for more than two decades, and indicated there will be repercussions for perpetrators.

"I feel compelled to personally take on all the evil that some priests — quite a few in number, (although) obviously not compared to the number of all priests — to personally ask for forgiveness for the damage they have done for having sexually abused children," he told members of the International Catholic Child Bureau.