Pope Francis dedicated a section of his Christmas message on December 25 to highlight the plight of migrants and refugees.
"It is injustice that makes them cross deserts and seas that become cemeteries. It is injustice that forces them to endure unspeakable forms of abuse, enslavement of every kind and torture in inhumane detention camps," Francis said.
"It is injustice that turns them away from places where they might have hope of a dignified life, but instead find themselves before walls of indifference," he added.
The leader of the world's 1.3 billion Catholics delivered the traditional papal Urbi et Orbi (to the city and the world) message to tens of thousands of people in St. Peter's Square.
To underscore his message, the two cardinals Francis chose to join him on the basilica's central balcony were Renato Martino, president emeritus of the Vatican's immigration office, and Konrad Krajewski, the papal almoner who distributes aid to Rome's poor and homeless.
Francis, 83, also called for peace in the Holy Land, Syria, Iraq, Ukraine, and other countries caught up in conflicts.
The pope denounced attacks on Christians by "extremist groups" in Western Africa.
He urged "comfort to those who are persecuted for their religious faith, especially missionaries and members of the faithful who have been kidnapped, and to the victims of attacks by extremist groups, particularly in Burkina Faso, Mali, Niger and Nigeria."
The Urbi et Orbi message is issued at Christmas and Easter, as well as after a papal election.