Pope Francis announced Sunday that he and his top aides will take a spiritual retreat to correct "the many defects we all have."

The pontiff told the tens of thousands at St Peter's Square that the retreat will begin next Sunday, and last until Friday morning. 

The Church leaders will visit Ariccia, Italy, and spend time reflecting, meditating, and praying. 

Although Francis did not list the defects that will be addressed, he recently warned hundreds of cardinals and bishops against having a "prejudiced mentality" that marginalises others.

"There are two ways of thinking and of having faith: we can fear to lose the saved and we can want to save the lost," he explained last week. "Even today it can happen that we stand at the crossroads of these two ways of thinking.

The Pope used the biblical story of Jesus healing a leper as an example of how Christians should treat society's outcasts.

"Jesus responds immediately to the leper's plea, without waiting to study the situation and all its possible consequences," Pope Francis said.

"For Jesus, what matters above all is reachingout to save those far off, healing the wounds of the sick, restoring everyone to God's family."

Francis has consistently called for unity against injustice, and has made the plight of underprivileged populations, exploited workers, and victims of modern slavery central causes for the Vatican.