Returning from a trip to Georgia and Azerbaijan on Sunday, the Pope said that the Catholic Church would make a rare exception in Hamel's case and not wait the usual five years before collecting testimony in support of his beatification.
"It is very important because the testimonies are still fresh in the memory of people who lived through [the attack]," he added.
Worshippers at the church where Hamel was killed, which reopened in a special ceremony on Sunday, broke out in applause when Rouen Archbishop Dominique Lebrun announced the news.
Minister angered by gender theory claim
Another of the Pope's comments during the flight back to Rome was less well received, by the French government at least.
Education Minister Najat Vallaud-Belkacem on Monday expressed regret that Pope Francis had been the victim of a "massive campaign of disinformation by [Christian] fundamentalists" after he said that "gender theory" is being taught in French schools.
The pope told reporters that a French Catholic man had reported that his 10-year-old son had replied "to be a girl" when asked what he wanted to be when he grows up.
"The father then found that in secondary school books gender theory is still being taught, while it is against nature," he went on.
The term "gender theory" is used by opponents to designate arguments that gender roles are socially acquired.
In 2014 some opponents of the government's gay marriage bill claimed that it was being taught in French schools as part of a campaign against the nuclear family and in favour of homosexuality.
While declaring that "having homosexual tendencies or changing sex is one thing", the pope said that teaching "this line" in schools is an attempt to "change mentalities" and "ideological colonisation".
Talk to teachers
"I advise the Pope to come and meet teachers in French school next time he comes to France," Vallaud-Belkacem commented on France Inter radio. "To take a look at the schoolbooks ... and explain to me where the gender theory, which doesn't exist by the way, is in these books."
The French education system "speaks of the need not to create a hierarchy between one sex and another, to fight against sexism and to fight against sexual harassment", she said.
French law has prescribed the teaching of equality between men and women since 1989 and sex education since 2001.