Pope Benedict XVI on Saturday apologised to victims of sexual abuse by priests in Ireland, saying he is "truly sorry" for what they have endured.
"You have suffered grievously and I am truly sorry," the pontiff said in a letter to be read out in churches and parishes throughout Ireland.
The pastoral letter is the most detailed response to date from the Vatican to the long-brewing scandal.
In the widely anticipated document, Benedict expressed "the shame and remorse that we all feel".
"I can only share in the dismay and the sense of betrayal that so many of you have experienced on learning of these sinful and criminal acts and the way the Church authorities in Ireland dealt with them."
He also addressed priests and other religious figures who have abused children, according to an Irish government-commissioned report that has detailed more than 300 cases since 1975.
"You betrayed the trust that was placed in you by innocent young people and their parents," Benedict said.
"You must answer for it before almighty god and before properly constituted tribunals," he added.
Benedict then announced that he would dispatch papal inspectors to dioceses in Ireland, as well as seminaries and religious congregations.
Irish church officials welcomed the move.
"I welcome this letter. I am deeply grateful to the Holy Father for his profound kindness and concern," said All-Ireland Primate Cardinal Sean Brady.
The archbishop of Dublin, Diarmuid Martin, described the pope's letter as "a further step in the process of renewal and healing".
"The pope recognises the failures of church authorities in how they dealt with sinful and criminal acts," Martin said.
But Michael Kelly of the Irish Catholic, the country's leading religious newspaper, told broadcaster BBC that "concrete gestures" were now needed in order to restore the church's battered moral authority in the country.
The pontiff did not mention specific disciplinary measures against bishops and other clerics who have been accused of a cover-up of cases of paedophilia.
His spokesman, Father Federico Lombardi, said the letter was meant as a "heartfelt" message by the pontiff to Irish Catholics rather than a set of bureaucratic procedures.
"This is just the first step of a long process," Lombardi said in Rome.
The Vatican has had to confront an increasing number of revelations about alleged abuses by priests at Catholic schools and institutions in several countries, including the pontiff's native Germany, Austria, the Netherlands and Brazil.
And while the Vatican noted that Saturday's letter was directed at Ireland, Germany's top Catholic cleric, Archbishop Robert Zollitsch, noted that the pope's pastoral letter gave "clear instructions for the entire church".
"What he is telling (Catholics in Ireland) is valid for the entire church and is clearly also a message to us in Germany," Zollitsch said in a statement.