Pope Francis said the Catholic Church will probably continue banning women from serving as priests forever, according to journalists who were traveling on a plane with him Tuesday.

According to the National Catholic Reporter, a Swedish journalist on the plane asked, “Is it realistic to think that there might be women priests also in the Catholic Church in the next few decades?”

When Francis said no, the journalist reportedly asked, “But really forever? Never?”

The pope reportedly replied, “If we read carefully the declaration made by St. John Paul II, it goes in that direction.”

Francis was referring to the earlier pope’s 1994 letter that noted that Jesus chose only men as his apostles. “The exclusion of women from the priesthood is in accordance with God’s plan for his Church,” John Paul II wrote in that letter.

Some advocates for the ordination of women saw a glimmer of hope in Francis’ decision earlier this year to create a commission to study the role of female deacons in the church. Deacons are clergy in the Catholic church, who can perform many of the functions of priests Women served as deacons in the early centuries of the church, but are currently banned from doing so.

Some saw the new commission, which Francis appointed seven men and six women to in August, as a harbinger of priesthood for women in the future.

Boston College theologian James Bretzke said when Francis created the committee, “If women can be ordained as deacons, then this is going to weaken – not destroy -– but weaken significantly the argument that women absolutely are incapable of being ordained as priests. So this is opening more than a crack in the door.”

This is not the first time Francis has stated his objection to the idea of women ever becoming priests. The subject came up again Tuesday because he was in Sweden to commemorate the 499th anniversary of the Protestant Reformation with Lutheran church leaders. The leader of the Lutheran church in Sweden is Archbishop Antje Jackelen, the first woman to fill the role.