Pope Francis calls for 'concrete and effective measures' at historic sex abuse summit More than 190 bishops and cardinals are in Rome to address clerical sex abuse.

On the first day of a historic conference that’s likely to become a defining moment of his papacy, Pope Francis appeared prepared to tackle the excruciating, decades-long epidemic of child sex abuse at the hands of Catholic priests.

“We hear the cry of little ones calling for justice,” the pope said as he gaveled to order the church’s first ever worldwide conference on the protection of minors.

More than 190 bishops and cardinals were summoned to Rome to participate in the meeting. The pope told them that more than one billion Catholic faithful “expect not simple and obvious condemnations, but concrete and effective measures.”

Abuse survivor Mary Dispenza said he’s got that right.

“This is an opportune moment for this pope to step forward and give us some concrete actions of what he is going to do to face the past and move into the future,” she told the Associated Press.

The clerical sexual abuse scandal has resurfaced in recent months, following a damning report last summer from a Pennsylvania grand jury, which accused more than 300 priests of molesting more than 1,000 victims in that state alone over the past 70 years.

The report prompted law enforcement in multiple other jurisdictions to launch their own forensic accounting of historic abuse cases.

The issue of sexual abuse by priests has reached the highest levels of the Vatican. Australian Cardinal George Pell, the most senior cleric to be convicted of sexual abuse, faces likely prison time. He's due to be sentenced this month.

This is an opportune moment for this pope to step forward and give us some concrete actions of what he is going to do to face the past and move into the future.

Last week, Pope Francis defrocked former Washington D.C. Cardinal Theodore McCarrick, after a Vatican tribunal found him guilty of sexually abusing a minor decades ago.

McCarrick was already the first cardinal in more than a century to be kicked out of the College of Cardinals, after a preliminary investigation by the Archdiocese of New York found the allegations against him to be credible.

It’s not clear what, if any, concrete actions will come out of the four-day Vatican conference. The church is a worldwide institution, and bishops in some parts of the world have resisted greater openness on sexual abuse because of local sensitivities.

Survivors of sexual abuse have urged the church to adopt a zero tolerance approach by mandating the reporting of credible allegations immediately to law enforcement for further investigation.

I’ve been talking about this for 28 years now. I know some some organizations move slowly but this is ridiculous.

Survivors have also called for the Church to name priests who have been credibly accused and to hold bishops accountable for cases in which pedophile priests have been transferred from one parish to another.

Phil Saviano, one of the survivors who shared his story with the Boston Globe Spotlight team more than a decade ago, told ABC News the priest who abused him was transferred by six different bishops to four different states before law enforcement finally caught up with him.

Saviano was one of a dozen survivors invited to sit down with Vatican organizers ahead of the conference.

“This is my third time in Rome on this issue and it was my first opportunity to speak with someone who has a little bit of power,” Saviano said.

“As is often the case, things are said, promises are made, but you really have to see what actually happens,” he said.

Saviano said he’s pleased the church appears to be taking the issue seriously.

“I’ve been talking about this for 28 years now,” he said. “I know some some organizations move slowly but this is ridiculous.”