In a strongly worded message during his traditional Sunday blessing, Francis said the news from Iraq "leaves us in disbelief."
He cited "the thousands of people, including Christians, who have been brutally forced from their homes, children who have died from thirst during the escape and women who have been seized."
The pope urged the international community to find a political solution "to stop these crimes."
Cardinal Fernando Filoni, the Vatican's ambassador in Baghdad during the Iraqi war, will travel to Iraq to show solidarity with Christians, among those targeted by Islamic State militants for elimination.
