Pope Francis says priestly celibacy is up for discussion.
For the first time since his election, the pope said that it is "not a dogma" that members of the clergy must abstain from sex. He made the remark in a chat with reporters on his way back to the Vatican from a historic trip to the Middle East.
"It is a rule of life that I appreciate very much, and I think it is a gift for the church, but since it is not a dogma, the door is always open," Francis said on Monday.
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The Catholic Church has been under pressure to abandon the celibate tradition. Some critics have argued, in the face of widespread sexual abuse of children by priests, that sexual frustration may be partly to blame.
Francis, in some of his harshest language to date on that scandal, said aboard the papal plane that sexual abuse by clerics is "like a satanic Mass." He will meet with abuse victims next month at the Vatican.
"We must go ahead with zero tolerance," he said on the plane.
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Priestly celibacy is a tradition dating 1,000 years, but it is not considered dogma, or unchangeable. Priests can marry in the Anglican and some other Protestant churches, and in the Orthodox Church.
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Francis made similar remarks about celibacy when he was archbishop of Buenos Aires. After his elevation to pope, his secretary of state said in September that celibacy "is not an institution."
The pope has sought to change the direction of the church, urging a focus less on culture-war issues like abortion and gay marriage and more on pastoral outreach and helping the poor.
—By Erin McClam, NBC News. Reuters contributed to this report.