Pope Francis is defending his decision to perform an airborne wedding while flying over Chile, saying the two flight attendants were prepared for the sacrament and that refusing them might have meant they would never get around to it again.

Francis told reporters that he had questioned both bride and groom before Thursday's in-flight nuptials and had pressed them on their family life, beliefs about commitment and Catholic Church teaching. He said they had completed the church's pre-wedding preparation course, had gone to confession, and were in what the church considers to be a "regular situation" allowing them to be married.

He said: "So why not do today what you can do today rather than put it off to tomorrow, when tomorrow might have turned into 10-20 years from now?"