The Pope's appeal, made at the end of his weekly general audience, came at the time of growing debate in Europe on how to deal with a migrant crisis that has included clashes at the French-Italian border between police and migrants.

"Let us pray for the many brothers and sisters who seek refuge far away from their land, looking for a home where they can live without fear, that their dignity may always be respected. I encourage the work of all those who bring their help and I hope that the international community will act in a harmonious and effective way to prevent the causes of forced migration," the Pope said at the end of his weekly general audience at the Vatican.

France and Austria have stepped up border controls on migrants coming from Italy, turning back hundreds and leaving growing numbers camped out in railway stations in Rome and Milan.

In a sign of persisting discord over how to deal with the migrant crisis, Italian Prime Minister Matteo Renzi threatened retaliation if other EU countries did not agree to take their fair share of refugees that land on Italy's shores.

France, Italy and Germany agreed yesterday to join forces to identify migrants arriving by sea and to swiftly relocate them across the European Union or send them back to their home countries if their claims for asylum in Europe are rejected.

As they deliberated, police began removing mainly African migrants from makeshift seaside camps on the Italian-French border.

Around 300 had gathered on the Italian side in hopes of proceeding into France and onwards to northern Europe where relatives live and job chances might be better.