Updated at 8pm
The Vatican expressed "shame and sorrow" on Friday over revelations that Roman Catholic priests in Pennsylvania sexually abused about 1,000 people over seven decades, vowing to hold abusers and those who protected them accountable.
Vatican spokesman Greg Burke broke the Vatican's silence over a damning US grand jury report that has shaken the American Church and said the Holy See was taking the report "with great seriousness".
He added that Pope Francis was on the side of survivors and victims and had a desire to "root out this tragic horror which has destroyed the lives of so many."
The grand jury on Tuesday released the findings of the largest-ever investigation of sex abuse in the US Catholic Church, finding that 301 priests in the state had sexually abused minors over the past 70 years.
Read: Priests abused thousands of children over decades in Pennsylvania
On Thursday, US Roman Catholic bishops called for a Vatican-led probe backed by lay investigators into allegations of sexual abuse by former Washington Cardinal Theodore McCarrick, who resigned last month.
Later on Friday, Pennsylvania's top Roman Catholic official vowed to ensure the widespread sexual abuse by hundreds of priests and cover-up revealed in this week's bombshell grand jury report would never happen again.
"The substance of the report is brutally graphic and profoundly disturbing as a chronicle of evil inflicted on hundreds of innocents," Philadelphia Archbishop Charles Chaput said in a weekly letter to Catholics. "The only acceptable responses are grief and support for the victims and comprehensive efforts to ensure that such things never recur."
Chaput's archdiocese was not covered by the Tuesday report, although a 2005 grand jury report found evidence that hundreds of children had been sexually abused by at least 63 priests in the district.
Reuters this week contacted the attorneys general of the 49 other U.S. states to see if they were considering similar actions. Only two, in New York and New Mexico, said they had taken some initial steps toward doing so.
Most declined to confirm or deny any investigations, said their state laws limited their ability to take on wide-ranging criminal investigations or did not respond to requests for comment.