Pope Francis will visit the Greek island of Lesbos on April 16, the Vatican said today, in a trip aimed at supporting refugees and drawing attention to the front line of Europe's migrant crisis.

Hundreds of thousands of refugees, many fleeing the war in Syria, have poured onto the Aegean island over the past year, but, under a contested plan, the European Union started returning newcomers to neighbouring Turkey this month.

The pope has repeatedly spoken out in support of refugees, urging Roman Catholic churches around Europe to take in migrant families. His first trip after he became pontiff in 2013 was to the Sicilian island of Lampedusa, which, like Lesbos, has received hundreds of thousands of migrants.