The Vatican will shelter two families of refugees who are "fleeing death" from war or hunger, Pope Francis announced Sunday as he called on Catholic parishes, convents and monasteries across Europe to do the same.

Francis cited Mother Teresa, the European-born nun who cared for the poorest in India, in making his appeal in remarks to pilgrims and tourists in St. Peter's Square.

"Faced with the tragedy of tens of thousands of refugees who are fleeting death by war and by hunger, and who are on a path toward a hope for life, the Gospel calls us to be neighbors to the smallest and most abandoned, to give them concrete hope," Frances said.

It's not enough to say "Have courage, hang in there," he added.

"May every parish, every religious community, every monastery, every sanctuary in Europe host a family, starting with my diocese of Rome," Francis said. He also asked bishops throughout Europe to have their dioceses take up his call to "express the Gospel in concrete terms and take in a family of refugees."

The Vatican is a tiny city-state and some of its citizens, including families with children, live in apartments inside its ancient walls. It has two parish churches, including St. Peter's Basilica.

Francis said two of the Vatican's parishes will welcome two refugee families, but did not give details. A Vatican spokesman, the Rev. Ciro Benedettini, quoted the pope's chief alms-giver as saying the Vatican is now deciding which families will be hosted.

He has chosen mercy as the overarching theme of his papacy. Practicing what he preaches, he has already made free showers at the Vatican available to Rome's homeless and has barbers available for haircuts for the needy, among other initiatives.

Thousands of migrants and refugees, many fleeing war and persecution, have streamed into Germany and Austria over the weekend after being stuck in Hungary for days.