Story highlights Pope Francis reiterates his view of transgender teachings

(CNN) Pope Francis reaffirmed his disagreement with teaching gender identity in schools on Sunday, after earlier calling it a "war against marriage."

On a return flight to Rome at the end of a three-day trip to Georgia and Azerbaijan, the Pope recounted a meeting with a French father whose young son wanted to be a girl after reading about it in a textbook.

"This is against nature," he said. "It is one thing when someone has this tendency ... and it is another matter to teach this in school."

"To change the mentality -- I call this ideological colonization," the Pope said.

The Pope said he still spends time with transgender people, leading them closer to God.

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