In an offhand remark on the papal plane en route to Mozambique, Pope Francis acknowledged the sharp opposition he has faced from conservative Catholic detractors in the United States, calling it an “an honour that the Americans attack me”.

His remark came at the start of a six-day trip to Africa, as the pope shook hands in the back of the plane with a French reporter who handed him a copy of his new book How America Wanted to Change the Pope.

He warmly told the reporter, Nicholas Senèze, who covers the Vatican for the French Catholic newspaper La Croix, that he had been unable to find the book, which explores American financial, political and media backing of the small but noisy conservative opposition seeking to undermine Pope Francis.

Apparently referring to his critics, he quipped that their disapproval is “an honour”.

He then handed the book to an aide and jokingly called it “a bomb”.

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Pope Francis’ priorities and inclusive approach to the papacy have infuriated some American prelates, donors and their supporters in conservative Catholic media.

Those critics often complain that Pope Francis is watering down church orthodoxy, retreating in the culture wars and sowing confusion in the Catholic church.

But it was Pope Francis himself who brought the old ideological rifts along for the ride.

Cardinal Raymond Burke, an American who has been repeatedly demoted by the pope, has been the de facto leader of the dissent against the pontiff.

But other conservative prelates in the American hierarchy have not been shy to criticise Pope Francis on a broad variety of issues.

Last August, the former Vatican ambassador to the United States, Carlo Maria Viganò, demanded the pope’s resignation. He has been hailed as a hero in some American conservative circles.

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It has been no secret that Pope Francis, the first Latin American pope, has a complicated view of his former neighbours to the north, and that the American conservatives have long been out of his good graces.

He has been a committed critic of the abuses of American capitalism.

Not long after his election, Vatican ambassadors briefed the pontiff about various situations around the world and suggested that he be especially careful when appointing bishops and cardinals in the United States.

“I know that already,” the pope interrupted, a high-ranking Vatican official told the Times in 2017. “That’s where the opposition is coming from.”

That year, two close associates of Pope Francis, in an article published in a Vatican-vetted magazine, accused American Catholic ultraconservatives of making an unholy alliance of “hate” with evangelical Christians to help Donald Trump.

One of the writers of that article, Antonio Spadaro, a prominent Jesuit who edits the magazine Civiltà Cattolica, sat with Pope Francis in the front section of the plane on Wednesday.

Almost immediately after the pope finished his meet-and-greet, asked for prayers for victims of hurricane Dorian and returned to his seat, the Vatican spokesman appeared in an apparent effort to clean up his remarks.

“In an informal context the pope wanted to say that he always considers criticism an honour,” said Matteo Bruni, the Vatican spokesman. “Particularly when it comes from authoritative thinkers, in this case from an important nation.”

The pope’s casual conversation with reporters on the plane soon after taking off from Rome on papal trips is a tradition and usually features the pope’s receiving gifts and requests for blessings from reporters in the Catholic media, and engaging in harmless and often awkward chitchat.

When I told the pope on Wednesday that I nearly missed the flight because, like him a few days earlier, I had been stuck in an elevator, he chuckled and made an Italian hand gesture to show how scary it was.

But other conversations yielded more pointed remarks.

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In another conversation overheard on the plane, the pope spoke with a German reporter, Andreas Englisch, about the pope’s decision to elevate to the rank of cardinal Michael Fitzgerald, a longtime proponent of interreligious dialogue with Muslims.

Pope Francis called the elevation of the cardinal, who had been sidelined under Pope Benedict XVI, “an act of justice”.

Mr Englisch said that he also told {p[e Francis that not all Germans believed the bad things said about him by German cardinal Gerhard Ludwig Müller, the church’s former chief theologian, who he fired.

When the pope asked Englisch what Müller had been saying about him, Englisch told him the cardinal had been saying he would try and save Francis’ papacy from bad theology.

According to the reporter, the pope said the cardinal “has good intentions and he is a good man, but he is like a child”.