VATICAN CITY — Pope Francis and the United Nations chief issued a joint year-end message Friday urging the world to remember children dying of hunger, migrants seeking safety and a planet threatened by nuclear weapons and climate change.

Francis hosted Secretary-General António Guterres at an audience and the two issued a joint video message from the pope’s private library. The themes touched on a host of issues on which the Vatican and U.N. have found increasing common ground under the first pope from the “global south.”

The two leaders denounced the “scandal” of hunger and the plight of migrants forced to flee their homes because of conflicts, global warming or religious persecution. They declared as “immoral” both the use and possession of nuclear weapons and vowed to fight together against the “plague” of all types of abuses against children.

The Vatican has been harshly criticized by a U.N. human rights committee for the clergy sexual abuse scandal, though this week Francis responded to one of the committee’s main complaints and abolished the rule of pontifical secrecy covering the cases.

After decades of sometimes hostile relations over the U.N.’s women’s reproductive health policies, the Vatican under Francis has increasingly involved U.N. officials in conferences and policy statements and embraced some of its key priorities.