Pope Francis' top sex abuse adviser has insisted the pope is "thoroughly committed" to ridding the church of abuse, but says his advisory commission must regroup following the clamorous resignation of Irish survivor Marie Collins.

Cardinal Sean O'Malley told a seminar Thursday that the commission has always maintained a "victims first" priority and that the issue of continued survivor involvement would be discussed at the group's plenary meeting starting Friday.

Collins resigned from the commission March 1 citing the "unacceptable" lack of cooperation from some Vatican offices in implementing the experts' proposals. Her departure dealt a blow to the commission's credibility and again raised questions about the commitment of the pope and the Vatican to fighting abuse and accepting outside expertise.

Several Vatican cardinals, including Francis' deputy, attended the conference.