Pope Francis told thousands of children who gathered at the Vatican on Friday that he did not want to be the head of the Church before his election.

"Someone who wants, who has the desire to be Pope doesn't love themselves, but I didn't want to be Pope," he said at a June 7 meeting in Paul VI Hall.

"Do you know what it means if someone doesn't love themselves very much?" he asked the 7,000 children from Jesuit-run schools in Italy and Albania in response to a girl's question.

The students were accompanied by their teachers and family members, as well as alumni of the schools, on the trip to the Vatican.

Pope Francis chose to speak off-the-cuff for a little over five minutes instead of reading a five-page set of remarks.

He then answered questions posed by a few children, who waited on the side of the stage, close to where he was sitting.

One of them asked him why he had chosen to live in Saint Martha's House instead of the Papal Apartments in the Apostolic Palace.

"I can't live alone, do you understand?" he remarked. "It's not a question of my personal virtue, it's just that I can't live alone."

"A professor asked me this question, 'why don't you go live there?' and I answered, 'listen, professor, it's for psychiatric reasons' because that's my personality," the Pope said.

He told the children jokingly not to worry because "that apartment (in the Apostolic Palace) isn't so luxurious."

"In a world where there is so much wealth, so many resources to feed everyone, it is unfathomable that there are so many hungry children, that there are so many children without an education, so many poor people," he remarked.

"Poverty today is a cry, we all have to think if we can become a little poorer, all of us have to do this," he added.

He asked them, "how can I become a little poorer in order to be more like Jesus, who was the poor teacher?"

A young boy asked Pope Francis if it had been difficult to leave his family when he decided to become a Jesuit at the age of 21.

"It's always hard, it was hard for me," he affirmed.

"Jesus gives you joy, but sometimes you feel dryness and alone. But it's beautiful following Jesus and then more beautiful moments arrive," he said.

He then turned the question back to the children.

"How do you think about walking ahead with difficulties?" he asked them. "With the Lord, all is possible."