Unused church buildings should be used to house refugees, who must be embraced rather than feared, Pope Francis told asylum seekers in Rome on Tuesday, underlining his papacy's emphasis on the poor and the plight of immigrants.

Turning convents and monasteries that have emptied due to a drop in vocations into hotels has raised funds for the Church, but also attracted criticism.

"Empty convents and monasteries should not be turned into hotels by the Church to earn money . . . [the buildings] are not ours, they are for the flesh of Christ, which is what the refugees are," Francis told a private audience in the Jesuit Astalli Centre for refugees, in a speech released to the press.

He met several asylum seekers, including some from Syria, after making an impassioned appeal for peace in the war-torn country at the weekend.

Francis said looking after the poor should not be the work of only "specialists," but engaged in by all members of the Church. It should also be part of the training of priests.

"The word solidarity frightens people in the developed world," the leader of the Catholic Church said.

Since expressing his wish for a "poor Church, and for the poor" shortly after his election in March, Francis' papacy has been marked by his humble style and the prominence given to the destitute.

In July he visited the Italian island of Lampedusa, where tens of thousands of illegal migrants arrive yearly, and condemned indifference to many who die making the treacherous journey across the Mediterranean seeking a better life.