Pope Francis acknowledged on Tuesday that the sex abuse scandals rocking the Catholic Church were driving people away and said the church must change its ways if it wants to keep future generations.

Francis referred directly to the crisis convulsing his papacy on the fourth and final day of his Baltic pilgrimage, which coincided with the release of a devastating new report into decades of sex abuse and cover-up in Germany.

He told a gathering of young people in Estonia, considered one of the least religious countries in the world, that he knew many young people felt the church had nothing to offer them and simply doesn't understand their problems today.

Those complaints recently poured into the Vatican via surveys commissioned ahead of a big meeting of bishops starting next week on how to better minister to young Catholics.

Francis told a gathering of Catholic, Lutheran and Orthodox young people that "many young people do not turn to us for anything because they don't feel we have anything meaningful to say to them".

He said the church wants to respond to those complaints transparently and honestly, adding that "we ourselves need to be converted".