Pope Francis on Wednesday expressed his personal shame and that of the Church at the sexual abuse of children by French Catholic clergy, after the scale of the problem was laid bare in a devastating report.

"I wish to express to the victims my sadness and pain for the trauma they have suffered," he said during his weekly audience at the Vatican.

"And also my shame, our shame, my shame for the inability of the Church for too long to put them at the centre of its concerns.

"I pray and we all pray together -- to you Lord the glory, to us the shame. This is the time for shame."

An independent commission on Tuesday revealed that French Catholic clergy sexually abused around 216,000 minors over seven decades since 1950, a "massive phenomenon" that was covered up by a "veil of silence".

The commission's two-and-a-half-year inquiry and 2,500-page report prompted outrage as the Catholic Church in France and around the world faces a growing number of abuse claims and prosecutions.

Dealing with the avalanche of revelations about sexual abuse by clergy was one of the biggest challenges that Francis faced when he was elected pope in 2013.

He declared an end to impunity and changed Vatican law to make reporting abuse mandatory, but victims have warned it is not enough.

Francis expressed his sorrow for the victims in a statement Tuesday issued through his spokesman, but his comments on Wednesday went further.

He urged the clergy to keep working to ensure such situations "are not repeated", offering his support to French priests to face up to "this trial that is hard but healthy".

And he invited French Catholics to "assume their responsibilities to ensure that the Church is a safe home for all".

Cruel indifference

The report found that the "vast majority" of victims were pre-adolescent boys from a variety of social backgrounds. Their abusers were mainly priests, bishops, deacons and monks. 

When claims against lay members of the Church, such as teachers at Catholic schools, are included the number of child abuse victims climbs to 330,000 since 1950, the report found.

"Until the early 2000s, the Catholic Church showed a profound and even cruel indifference towards the victims," commission chief Jean-Marc Sauve told a press conference that unveiled the nearly 2,500-page report.

Archbishop Eric de Moulins-Beaufort, president of the Bishops' Conference of France (CEF), which co-requested the report, expressed his "shame and horror" at the findings.

"My wish today is to ask forgiveness from each of you," he told the news conference.

Sauve had already told AFP on Sunday that a "minimum estimate" of 2,900 to 3,200 clergy members had sexually abused children in the French Church since 1950.

Yet only a handful of cases prompted disciplinary action under canonical law, let alone criminal prosecution.

The commission began its work after Pope Francis vowed to address abuse by priests in May 2019, ordering people aware of cases to report them to Church officials.