Speaking on the final day of his first US trip Pope Francis used an address in Philadelphia to tell gathered bishops that 'God weeps' for the victims of clerical sexual abuse and those responsible will be 'punished'.
The Pope's comments came after he met with abuse victims and the day after he led a packed Mass at Madison Square Garden in New York.
The Pope addressed thousands of Catholics in Washington as he led his first mass in the United States.
The Pope is celebrating Mass outside the Basilica of the National Shrine of the Immaculate Conception.
During the service he will elevate an 18th-century Franciscan friar to sainthood, in a first canonisation in the United States.
More than 2,000 men and women studying to be Catholic priests and nuns were invited from around the country to attend.
Pope Francis' first US visit has sparked an unexpected craze among Americans - dressing dogs up in miniature versions of his papal garb.
A five-year-old girl managed to breach the Pope's security to deliver him an important letter.
Pope Francis is due to arrive in the US, but he will face a political test on Thursday when he addresses Congress.