Asked why he thought God would allow children to suffer, the Pope conceded he was stumped.
"I have no explanation for that," Francis responded, according to The Associated Press.
"I have my faith and try to love God, my father. But why children suffer? I have no answer for that."
On the tensions with Russia, Francis did not explicitly take sides, merely stressing that "war is always destruction".
He prodded European nations to be more welcoming towards migrants, particularly refugees who have crossed the Mediterranean, usually in dangerous circumstances.
"Each country must say how many migrants they can take," he said.
Francis said gossip, bullying and aggression were great dangers to modern society, adding that "gossip destroys identity".
Asked whether he had friends, the Pope said he had a small circle of them, who were "few but true".
He also explained that he shuns the spacious papal apartments used by his predecessors because he is "no saint" and needs to be close to people.
To end the interview, he made his usual plea for viewers to not "forget to pray for me". From those who don't pray, he requested "at least send me good thoughts".