Pope Francis has thanked Jordan for welcoming hundreds of thousands of refugees fleeing the civil war in Syria, calling for an "urgent", peaceful solution to the conflict.

His comments come as he began a three-day visit to the Middle East, which will also take in the West Bank, Jerusalem and Amman, where he will conduct Mass before an estimated 25,000 people.

Pope Francis also lauded Jordan for the "serene co-existence" enjoyed by Christians and Muslims in the country and called for greater protections for minority Christians across the region.