Pope Francis said the Catholic Church's rules regarding marriage and divorce should not "lock the salvation of persons within the straits of legalism" in a message to top marital judges at the Vatican on Friday.

Francis said he wants Catholic marriage annulments and other marital proceedings to be free in his address to the Roman Rota. 

"This is a point I want to emphasise: the sacraments are free," he told the Church's final court of appeals for annulments.

"The sacraments give us grace," he continued. "And a marriage proceeding touches on the sacrament of marriage.

"How I wish all marriage proceedings were free of charge!"

The pontiff is moving to streamline the annulment process, make it more affordable, and increase accessibility. Some US dioceses have already waived annulment fees, which average around $400.

Pope Francis has in the past criticied the treatment of divorced Catholics, specifically prohibitions against them becoming godparents, or reading during Mass.

"It seems they are excommunicated de facto," he said last month, suggesting that the Church should "open the doors a little bit more." Francis did not address the issue of remarried Catholics receiving communion, but asked "Why can't they be godparents?"

Pope Francis has been deemed one of the most liberal popes, and has caused friction among the more conservative and tradition-minded church leaders. In October, US Cardinal Raymond said that the Catholic Church under Pope Francis is "a ship without a rudder".

The Pope welcomed the criticism.

"Resistance is now evident," he said. "And that is a good sign for me," that there isn't "hidden mumbling when there is disagreement... It's healthy to get things out into the open."