The U.S. archbishop helping to organize next week's summit of the world's bishops at the Vatican on sexual abuse by clergy said Thursday he expects to make "significant progress" in responding to the scandal that's riven the church, and that lay Catholics will help to hold the hierarchy accountable.

Chicago Cardinal Blase Cupich told The Associated Press in a phone interview that the Feb. 21-24 prevention summit, convened by Pope Francis, is necessary for all global Catholic church leaders to understand they must act and be accountable to the victims for the abuse cases stretching back decades. He spoke of the urgency while acknowledging that victims and their advocates consider such a gathering long overdue.

"I think there is understandable frustration on that level," said Cupich, hand-picked by Francis to help organize the summit. "All I can say now is I believe we're going to make significant progress here. And we should also realize that we always have to keep learning — we can't get to a place that we think we have this nailed down. If we do that we're going to get it wrong.

"This meeting will be a significant moment, I think, to put us on a fresh trajectory — in a whole new direction," he added.

The summit comes at a crisis moment for the U.S. church, following a Pennsylvania grand jury report that found hundreds of abusive priests in the state, and the scandal over ex-Cardinal Theodore McCarrick, accused of abusing minors and seminarians. In December, Cupich expressed regret for "our failures to address the scourge of clerical sexual abuse" in a statement responding to a report by the Illinois attorney general that said the church failed to disclose the names of at least 500 clergy accused of sexually abusing children.

Zach Hiner, executive director of the Survivors Network of those Abused by Priests, or SNAP, said in an email to the AP that church officials have repeatedly shown "they are incapable of accurately determining the credibility of accusations, being transparent with the public, and understanding the pain that survivors go through." The organization previously said Cupich should be removed from his summit-planning role.

"We remain cautiously optimistic that there will be real change as a result of this meeting, but regardless of what Vatican officials do, we are placing our faith in attorneys general and prosecuting attorneys around the country instead," Hiner said.

U.S. bishops, who last month held a prayer retreat outside Chicago as a prelude to the summit, had planned to adopt accountability measures at their November meeting that would have created a code of conduct for bishops and established an independent lay-led commission to investigate allegations against them. The Vatican blocked the vote on the grounds that the proposals were legally problematic and had only been given to the Vatican for review four days before the meeting began. The Vatican told the U.S. bishops to wait until after next week's meetings and work with the Holy See to develop proposals together.

Cupich then proposed instead a model using the metropolitan bishop — a senior bishop responsible for several dioceses — to handle allegations against bishops under his jurisdiction. In the interview, Cupich suggested the "metropolitan model" had gained favor at the Holy See, saying he expected the overall framework Francis would propose would use this existing church structure along with lay participation to ensure their expertise is included and transparency in the process.

"Whatever framework is going to be put together for us ... there has to be in the involvement of lay experts to make sure that there's full visibility by the people of God," he said. "And then it has to be done in a collegial manner" using the existing structure of what the church already has in place.

Cupich said victims also will be part of the summit, both in their presence and through video testimony. But he also was the lead signatory on a recent letter that urged attendees to meet with victims "to learn firsthand the suffering they have endured."

"My experience in 20 years of being a bishop — and I've met with scores of victims — is that it's those personal encounters that are transformative, not in a group session," he said.

Francis has sought to lower expectations for the summit, saying last month that the "problem of abuse will continue" because "it's a human problem." He said he wanted to sensitize church leaders around the globe to the pain of victims, instruct them how to investigate cases and develop general protocols for the entire hierarchy to use.

Francis in September summoned the presidents of bishops' conferences for the summit after realizing that church leaders in some parts of the world still didn't "get it." In fact, more than 30 years after the scandal first erupted in Ireland and Australia and 20 years after it hit the U.S., bishops in many parts of Europe, Latin America, Africa and Asia either deny the problem exists in their regions or downplay it.

Cupich, considered a moderate who was Francis' first major U.S. appointment, said it's inevitable that some will see the outcome of the summit as a referendum on Francis that correspondingly places a burden on the cardinal's shoulders. The letter he signed also included a warning that a failure to deal with abuse now will jeopardize the church's mission globally.

"We've got to be detached from that personal credit or blame because the real issue is what's at stake for the church," he said. "I really do want to put the emphasis on the victims and not our reputation."