VATICAN CITY (AFP) - Pope Francis highlighted the plight of refugees and migrants in his traditional Angelus prayer, as Catholics celebrated the Feast of the Holy Family on the first Sunday after Christmas.

Using the Holy Family as a comparison, Pope Francis told faithful gathered on the Vatican's St Peter's Square that upon fleeing Egypt, Joseph, Mary and Jesus "experienced the dramatic condition of refugees, marked by fear, uncertainty and difficulties".

Today "millions of families face this same sad reality", said the Pontiff, adding that refugees and migrants do not always "find a true welcome, respect, and appreciation for the value that they bring".

He also expressed regret at the way the world treats its elderly people, saying older generations were sometimes like "hidden exiles" treated "like burdens".

Pope Francis, a more moderate pontiff than his predecessor Benedict XVI, has appeared keen for the Church to forge a better relationship with the modern family.

He has called an extraordinary Synod of Bishops in October next year to address among other issues the problem of divorcees remarrying.

A few simple words go a long way in ensuring a happy family, the Pope told the crowd: "May I, thank you and sorry", which he made followers in the Square repeat.

The Feast of the Holy Family is celebrated the last Sunday of December.