(CNN) Pope Francis said Sunday morning that all those responsible for the sexual abuse of youth by clergy will be held accountable.

"God weeps" for sexual abuse of children, he said, vowing "careful oversight" to ensure that youth are protected.

"The people who had the responsibility to take care of these tender ones violated that trust and caused them great pain," he said during a meeting with bishops in Philadelphia.

Earlier Sunday, Francis met with victims of clergy sexual abuse, Bishop Edward Burns said via his Twitter account.

"I have heard in my heart these stories of suffering of those youth that were sexually abused, and it continues to be on my mind," Francis told the bishops.

"Those who have survived this abuse have become true heralds of mercy. Humbly we owe each of them our gratitude for their great value, as they have had to suffer terrible abuse, sexual abuse of minors," he said.

The Pope has met with abuse survivors before. His first meeting with victims was at the Vatican in July 2014. Pope Benedict XVI held such meetings at least five times during his papacy, according to bishopaccountability.org.