Pope Francis say he is open to married Catholic priests.

Pope Francis has said he is open to married men becoming priests to combat the Roman Catholic Church's shortage of clergy.

In an interview with German newspaper Die Zeit, Pope Francis said the lack of Catholic priests was an "enormous problem" for the Church, and indicated he would be open to a change in the rules governing eligibility for the priesthood.

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

Viri probati is the Latin term for "tested men" or married men of outstanding faith and virtue.

The option would allow men who are already married to be ordained as priests. But single men who are already priests would not be allowed to marry, according to the Pope.

"Voluntary celibacy is not a solution," he said.