They insisted the Church had learnt from the crisis and had taken action to prevent future abuse.
Victims’ advocates complained there was still too little transparency.
Last month, the Vatican refused a request from the UN’s Committee on the Rights of the Child (CRC) for data on abuse, on the grounds that it only released such information if requested to do so by another country as part of legal proceedings.
The Holy See gets it that there are things that need to be done differently”
The Vatican came to Geneva expecting a rough ride and it got one, the BBC’s Imogen Foulkes reports.
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.
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 ratified the convention in 1990 but after an implementation report in 1994 it did not submit any progress reports until 2012, following revelations of child sex abuse in Europe and beyond.
In a homily on Thursday, Pope Francis said abuse scandals were “the shame of the Church”.
‘Not very transparent’
“The view of committee is that the best way to prevent abuses is to reveal old ones – openness instead of sweeping offences under the carpet,” Kirsten Sandberg, chairwoman of the 18-strong CRC, told the Vatican delegation.
“It seems to date your procedures are not very transparent.”
The Vatican was asked why it continued to describe abuse as an offence against morals rather than a crime against children.
“Does the Holy See believe that paedophilia is something that can be successfully overcome?” was another question.
Archbishop Silvano Tomasi said: “To prevent abuse of minors is a real, immediate concern.”
On prosecution of offenders, he said priests were “not functionaries of the Vatican but citizens of their countries and fall under the jurisdiction of their own countries”.
When asked if the Vatican would hand over Archbishop Jozef Wesolowski, a Polish papal envoy recalled from the Dominican Republic in September amid claims of sexual abuse there, Archbishop Tomasi said he was being investigated by the Vatican’s own prosecutors.
A member of the CRC asked about the Church’s practice of moving priests suspected of abuse.
“It is a no-go simply to move people from one diocese to another,” said Bishop Charles Scicluna, the Vatican’s former chief prosecutor of clerical sexual abuse.
He insisted it was “not the policy of the Holy See to encourage cover-ups” but added: “The Holy See gets it that there are things that need to be done differently.”
‘Refused to answer’
While Thursday’s questions were numerous and far-ranging, they were asked in blocs, with the Vatican delegation given time to retire to prepare its answers.
Observers vented frustration at the lack of specific answers.
“Holy See: ‘We get it’ in UN review on child sexual abuse Catholic Church,” wrote the children’s rights watchdog CRIN in a tweet. “Do you? Why then don’t you make statistics public?”
Barbara Blaine, president of a group representing US victims of abuse by priests, told BBC News that the hearing had brought “hope to victims across the globe”.
But it would also stand, she said, as a “record of how the Church officials refused to answer the questions, how they claim to be open and transparent, and yet they don’t live up to that ideal”.