Church leaders from across the world are at the Vatican for the first day of an unprecedented summit on child sex abuse.

It's a global scandal that has rocked the Catholic Church, and while his predecessors have been accused of failing to properly address it, Pope Francis says the Church must take steps to protect its most vulnerable members.

(SOUNDBITE) (Italian) POPE FRANCIS SAYING: "...we hear the cry of the little ones who ask for justice... The holy people of God look at us and expect from us, not simple and obvious condemnations, but concrete and effective measures to put into place." The Pope has gathered nearly 190 church leaders, vatican officials and experts, bringing the extent of the abuse to the forefront of church policy after decades of coverups.

(SOUNDBITE) (English) CARDINAL OF THE PHILIPPINES, LUIS TAGLE, SAYING: "The wounds of the recent crisis carried a memory of innocents suffering, but they also carried the memory of our weakness and sinfulness.

Tens of thousands of victims abused as children by clergy members have come forward since the eighties, when the sex abuse crisis first came into the media spotlight.

Many feel this meeting won't go far enough.

(SOUNDBITE) (English) PETER SAUNDERS WHO SAYS HE IS A VICTIM OF CLERGY ABUSE AND BRITISH FOUNDER OF THE NATIONAL ASSOCIATION FOR PEOPLE ABUSED IN CHILDHOOD, SAYING: "Pope Francis is a very complicated and contradictory man.

He has said some very, very positive things about the issue, he's mentioned zero tolerance, but then we know he has personally sanctioned the re-instatement of priests or bishops that have abused or covered-up, so that's completely contradictory to his expression of concern, for the protection of children.

The Pope himself has said too much significance is being given to a meeting that cannot resolve decades of abuse in four days.

Regardless, it's seen as a key test of his leadership and could see the tide turn in the way the church handles abuse.