The Vatican is being confronted publicly for the first time over the sexual abuse of children by clergy, at a UN hearing in Geneva.
The Church was asked why it continued to describe such abuse as an offense against morals rather than a crime against children.
Archbishop Silvano Tomasi said such crimes could "never be justified" and every child should be "inviolable".
The Vatican earlier refused a request for data on abuse.
When it argued that such cases should be heard in the countries where they took place, it was accused of responding inadequately to abuse allegations.
This is the first time the Holy See is defending itself in public over its record on sex abuse.
Victims say they hope the hearing, which is being broadcast live, will prompt the Church to end its "secrecy".
Pope Francis announced last month that a Vatican committee would be set up to fight sexual abuse of children in the Church and offer help to victims. He also broadened the definition of crimes against minors to include sexual abuse of children.
The Holy See is a signatory to the UN Convention on the Rights of the Child, a legally binding instrument which commits it to protecting and nurturing the most vulnerable in society.
It was, Archbishop Tomasi said in his opening statement, important to establish the truth of what had happened in the past, to prevent it ever happening again, to see justice done and to provide healing for the victims.
The Vatican, he told the panel, would welcome any suggestions from the UN's Committee on the Rights of the Child (CRC) to implement its obligations.
CRC members then set out their questions, asking about the Church's practice of moving priests suspected of abuse and allegations that it had concealed such abuse.
"Does the Holy See believe that paedophilia is something that can be successfully overcome?" was one question.
How, the Vatican was asked, did it go about training priests for work with children? What oversight was in place for Catholic institutions such as schools, and what plans did it have to collect data on child sex abuse?
Last July, the CRC requested detailed information about the particulars of all sexual abuse cases notified to the Vatican since 1995.
The questions included whether priests, nuns and monks guilty of sexual crime were allowed to remain in contact with children, what legal action had been taken against them, and whether complainants were silenced.
In its response, the Holy See said it was not its practice to disclose information about the religious discipline of clergy unless specifically requested to by the authorities in the country where they were serving.
It stressed that it had changed the criteria for choosing priests and revised Church law to ensure clergy were properly disciplined.
It also insisted that as a diplomatic entity it was "separate and distinct" from the Roman Catholic Church.
This was dismissed as a false distinction by critics like Britain's National Secular Society, which said the Holy See operated a "firm command and control structure over the worldwide Church" ( via bbc.co.uk ).