The Archbishop of Boston, Cardinal Seán O'Malley has said the "clock is ticking" for those in leadership positions in the Catholic church.

The comments come after a Grand Jury revealed that more than 300 "predator" priests in Pennsylvania were accused of abusing more than 1,000 children across seven decades.

The Grand Jury’s report estimated that while over 1,000 child victims were identifiable, the "real number" was "in the thousands".

To date, only two priests have been charged with crimes that fall within the statute of limitations.

The grand jury called for changes in the law that would scrap the statute of limitations for child sex abuse, give victims more time to file civil lawsuits and tighten legislation compelling people to report abuse they find out about.

Archbishop O’Malley said Catholics had now lost patience with church leadership and that civil society had lost confidence in them.

He said: "There are times when words fail us - when they do not capture the depth of overwhelming situations we sometimes face in life. For the church in the United States this is one of those times."

He said the church leadership remained "shamed" by the failure to protect children and those who are vulnerable.

He said this must never be repeated.

Today’s comments come after the Vatican issued a statement expressing its "shame and sorrow" over the Pennsylvania revelations.

The Vatican vowed to hold accountable sexually abusive priests and bishops who enable them to continue to prey on minors.

Meanwhile, Irish abuse survivors said the Vatican’s statement fell short on accountability.

Archbishop O’Malley said that the current crisis was the product of clerical sins and clerical failures.

He said the accountability needed by the Catholic church is only possible with the significant involvement and leadership of lay men and women.