Pope Francis on Wednesday said it's an "honor" to be criticized by Catholic conservatives in the United States. He made the comments while on a 10-and-a-half hour flight from Rome to Maputo, Mozambique, where he begins a week-long tour of three African nations.

It's customary for the pope to come to the back of the plane to greet journalists traveling with him. Roughly 60 journalists are accompanying Francis on the journey and generally each one has a few moments to have an informal conversation with the pope.

Usually the conversations are innocuous small talk and don't make headlines. But, on this flight, a French journalist who covers the Vatican, handed Pope Francis a book he'd written titled, "Comment L'Amérique Veut Changer de Pape" or "How America Wants to Change the Pope." The book includes criticism from conservative American Catholics who dislike Francis for issues ranging from immigration to climate change, and would like to see a new pope elected. Seneze covers the Vatican for the French Catholic newspaper La Croix.

Pope Francis, left, greets CBS News correspondent Seth Doane aboard the papal plane while en route to southern Africa on Wednesday, Sept. 4, 2019. CBS News

The pope acknowledged to the reporter, Nicolas Senèze, that he had read about the book in a Rome newspaper, but that he had not been able to get a copy. Senèze, the author, told CBS News that Pope Francis said to him, "For me it's an honor they attack me, the Americans." He was referring to the critics in the book.

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The comment made a stir among journalists and a bit later in the flight, the Holy See Press Office clarified that the conversation was in an "informal context" and elaborated that the pope feels it is an honor to be criticized by anyone he respects and from a country he respects.

Sometimes these informal discussions can be amplified simply because dozens of journalists from around the world are sitting in close proximity on a 10-hour flight and each is looking for a chance to catch a glimpse of an unscripted pope.

These papal voyages are closely choreographed and Francis is likely to stay on script. Ahead of the departure, the Vatican underlined that the topics of "hope" and "reconciliation" will be themes throughout this journey.

Those themes are particularly relevant on his first stop, in Mozambique, a country which has been scarred by civil war. Pope Saint John Paul II was the last pontiff to visit Mozambique and the Vatican had been involved in brokering a peace deal which was ultimately shattered by more violence. Now, a new peace deal has been inked and an election will soon be held. Pope Francis is expected to discuss the need for dialogue and the importance of peace.

This tour of Africa is Francis' fourth visit to this continent. In addition to Mozambique, the pope will be visiting Madagascar and Mauritius.