Pope Francis said Sunday during a gathering of bishops that he has met with victims of church sex abuse, together with educators and members of their families.
The pope met the three women and two men, with their relatives and educators, for 30 minutes at the San Carlo Borromeo seminary, the Vatican said in a statement.
"For the sexual abuse of children, these cannot be maintained in secret, and I commit to a careful oversight to insure that youth are protected and all responsible will be held accountable," the pope told the bishops.
"Those who have survived the abuse have become true heralds of mercy, probably we owe each of them our gratitude for their great value as they have had to suffer terrible abuse," he added.
Philadelphia is one of the cities where the scandal was most serious in the 1980s.
One rare criticism of the pope during his six-day visit to Washington, New York and Philadelphia, which ends on Sunday with a giant open-air mass, was that he did not have such a meeting on his public agenda.
Without the audience, victims of the sex abuse scandal would have been extremely disappointed. The pope's predecessor, Benedict XVI, met victims of the sex abuse scandal in Boston in 2008.