Pope Benedict XVI says all countries have the right to regulate immigration flows and protect their borders, and immigrants must respect the laws and national identity of their host nations.
The pontiff said in a message that every person has a right to migrate in search of better living conditions.
The Vatican on Tuesday issued the pope's message for the church's World Day for Migrants and Refugees, which is celebrated Jan. 16.
Benedict said that, as the word's societies become more multiethnic and intercultural, people should seek dialogue and respect each other's differences. States must respect the dignity of all migrants and share their resources, while immigrants "have the duty to integrate into the host country."