The Catholic Church must take all necessary steps to prevent further occurrences of child sex abuse by clergy, Pope Benedict has said.
The Pope said trust had to be rebuilt
To do this, the church had to find out what had happened in the past, he said.
The Pope made the comments to a group of visiting bishops from Ireland, where abuse scandals dating back decades have damaged the reputation of the church.
Trust in the clergy had been damaged, Pope Benedict said, and rebuilding confidence was an urgent task.
In March, a report from the Archdiocese of Dublin said that more than 100 Catholic priests in Dublin were suspected of having abused children in the last 66 years.
But there have been other scandals in various parts of the world.
In the US, a Boston-based scandal in 2002 led to the prosecutions of a number of priests, large payouts to dozens of victims and allegations of a cover-up by senior clergy.
Pope Benedict said that abuse scandals had created deep wounds in the church.
"It is important to establish the truth of what happened in the past, to take whatever steps are necessary to prevent it from occurring again," he said, according to a copy of the speech released by the Vatican.
"Above all, (it is important) to bring healing to the victims and to all those affected by these egregious crimes."
But Pope Benedict said the abuse scandals should not overshadow the work of Ireland's priests.
"The fine work and selfless dedication of the great majority of priests and religious in Ireland should not be obscured by the transgressions of some of their brethren," he said.
Pope Benedict spoke in some of the strongest language he has used so far of his personal anguish and horror at what happened in Ireland, says the BBC's Christian Fraser in Rome.
But some have questioned whether the Pope's comments are too little too late, and whether an apology should be made directly to the victims themselves.
While welcoming the Pope's expression of regret, Colm O'Gorman, the founder of a victims' group in Northern Ireland, said more action was required by the Vatican to introduce a worldwide system of child protection measures that would be underpinned in church law, our correspondent adds.