Pope Francis has suggested he’s open to the possibility of the church ordaining men who are already married to women ― but only under very specific conditions.

With a few notable exceptions, men in the Roman Catholic Church take a vow of celibacy before they are ordained into the priesthood. Catholic priests are expected to remain unmarried for all their lives, following the example set by Jesus and many of his apostles.

In a wide-ranging interview with the German newspaper “Die Zeit,” Francis briefly discussed the topic of clerical celibacy, and whether married men could perform some of the jobs of a fully ordained priest in regions of the world where there is a shortage of priests.

There’s been a slight increase in ordinations in the United States, but not enough to replace priests who have died or left the ministry.

According to a translation provided by America Magazine, Francis said that he sympathized with the plight of Catholics who aren’t able to participate in the Eucharist because of a lack of priests in their area. He called the shortage an “enormous problem.” However, he doesn’t think making clerical celibacy optional in order to attract more young men to the priesthood is the way forward.

“The issue of voluntary celibacy is frequently discussed, especially if there is a shortage of clerics. But voluntary celibacy is not a solution,” he told the newspaper.

“Die Zeit” then asked Francis about the possibility of ordaining viri probati ― men of virtue who are married “but can be ordained deacons because of their exemplary Catholic moral conduct.”

Francis said that an expanded role for viri probati is something the church needs to consider.

“We need to consider if viri probati could be a possibility. If so, we would need to determine what duties they could undertake, for example, in remote communities,” Francis said.

Tony Gentile / Reuters Pope Francis blesses ashes during the Ash Wednesday mass at Santa Sabina Basilica in Rome, Italy March 1, 2017. REUTERS

Married men are already allowed to become deacons in the church. Deacons perform a number of important functions ― including preaching, baptizing, and leading prayers ― but only a priest is allowed to consecrate the Eucharist.

The Roman Catholic Church already allows some married clergy to become ordained ― such as former Anglican or Episcopal priests who were married before their ordination into the Catholic church. In addition, some married men in Eastern Rite Catholic churches are able to be ordained.

However, even in these exceptions, marriage isn’t normally allowed after ordination ― an ordained priest isn’t allowed to get married, for example, and widowed priests aren’t able to remarry.

Reuters Cardinals and bishops attend a mass led by Pope Francis to mark the closing of the Catholic Jubilee Year of Mercy in Saint Peter's Square at the Vatican November 20, 2016.

The principle of clerical celibacy evolved over time. The Gospels speak of Jesus healing St. Peter’s mother-in-law ― which meant that the man believed to be the church’s first pope had a wife at one point. Bishops, priest and deacons in the early church continued to get married several centuries after the religion was founded. It wasn’t until the 12th century that celibacy became a requirement for all clergy.

In the past, Pope Francis has made it clear that he was in favor of maintaining the centuries-old practice of priestly celibacy ― but that it’s a matter of tradition, and not a doctrine of the church that is immutable.

In 2012, before he became pope, the then-Cardinal Jorge Bergoglio said that priestly celibacy is “a matter of discipline, not of faith. It can change.”

But, he said, “Tradition has weight and validity.”