The pope used his annual speech to urge those who have carried out sex crimes against children to turn themselves into authorities.
He said: "Let it be clear that before these abominations the church will spare no effort to do all that is necessary to bring to justice whosoever has committed such crimes."
The pontiff's comments come after a year of damaging revelations concerning sexual misconduct and cover-up which have undermined confidence in the Catholic Church.
Earlier this year, he admitted making "grave errors" in his own handling of a clergy sex abuse scandal in Chile. Meanwhile, state prosecutors have been uncovering decades of cover up in the United States.
During his speech, Francis acknowledged failings by the Church to treat the issue seriously and to always believe victims.
Urging people with information about misconduct to come forward, he added: "The church asks that people not be silent, but bring it objectively to light, since the greater scandal in this matter is that of cloaking the truth,"
Pope Francis shall welcome to the Vatican church leaders from around the world in February 2019 for an abuse prevention summit.
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