The Catholic Church should consider allowing married men to become priests, Pope Francis said, in what would be a radical departure from current Vatican teaching.

The lifting of the ban on married men being ordained would apply only in specific circumstances, for instance in remote areas of the world where priests are in short supply, the Pope said. But it would effectively reverse the centuries-old principle that Roman Catholic priests must be celibate.

In an interview with Germany's Die Zeit newspaper, the pontiff said he was open to the idea of so-called "viri probati" - married men of deep faith who are already involved in the Church – being allowed to become priests.

"We must consider if viri probati is a possibility. Then we must determine what tasks they can perform, for example, in remote communities," he said.

Francis’s greater flexibility towards some of the Catholic Church’s thorniest contemporary problems has been a pillar of his four-year papacy.

The compassion he has brought to bear on issues such as whether Catholics who divorce and then remarry should be allowed to take Communion has earned him rock star status among liberals but earned the opprobrium of many conservatives, especially in the United States.