"So many other footsteps are hidden in the footsteps of Joseph and Mary," he said.

Pope Francis, 81, who hails from Argentina, is the grandson of Italian migrants.

"We see the tracks of millions of persons who do not choose to go away but, driven from their land, leave behind their dear ones," he told the gatherers.

According to reports, an estimated 22 million people now live as refugees across the globe.

Image: twitter.com/Pontifex