Pope Francis called for people fleeing conflict zones to be given "temporary visas" to help them reach safety, and slammed "collective and arbitrary expulsions" of migrants and refugees. The pontiff said humanitarian corridors should be set up for those in need -- a move that could prevent the deaths of people attempting perilous journeys across deserts and seas.

"Special temporary visas should be granted to people fleeing conflicts in neighboring countries," he said in his message for January's annual World Migrant and Refugee Day, which is traditionally published months in advance.

"Collective and arbitrary expulsions of migrants and refugees are not suitable solutions, particularly where people are returned to countries which cannot guarantee respect for human dignity and fundamental rights," he added. Francis did not specify which countries.

Experts said he may have been referring to European attempts to stop migration flows across the Mediterranean by blocking asylum seekers in crisis-hit Libya or other African hotspots.

The pope also called for an end to the automatic detention of those who enter countries without authorization, insisting alternative solutions could and should be found.