Devastating conflicts, violence and persecution in places like Syria and South Sudan had left a record 65.6 million people uprooted from their homes by the end of 2016.
Pope Francis has long railed against corruption and the mafia, but now the Vatican is considering developing a whole doctrine around excommunicating corrupt and mafia-tinged Catholics.
Doha has long faced accusations that it is a state sponsor of terror.
A suspected cholera outbreak is spreading quickly in war-ravaged Yemen, with an estimated 3,000 to 5,000 new cases every day.
Upon completing their meeting, the pope gave the president a medal featuring an olive branch, a symbol of peace, among other gifts.
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