Pope Francis led the traditional Easter Sunday Mass in St Peter's Square in the Vatican City during a torrential downpour.

It will be followed by the Urbi et Orbi (to the City and the World) blessing to a global audience of millions which will be livestreamed by the Vatican across the world.

Urbi et Orbi ("to the City [of Rome] and to the World") is a papal address and Apostolic Blessing given to the City of Rome and to the entire world on certain occasions including Easter.

The Urbi et Orbi address and blessing are given each Easter and Christmas from the central loggia of Saint Peter's Basilica in Rome, at noontime and are broadcast worldwide through the European Broadcasting Union and other linkups. The address concludes with greetings in many languages in relation to the feast celebrated.

On Saturday night, Pope Francis presided over an Easter Vigil service and on Friday denounced the "complicit silence" of the international community before the massacre of Christians by Islamic extremists.

Pope Francis, 78, acknowledged how demanding Holy Week can be on priests like himself on Thursday, but urged priests to revel in the "good and healthy tiredness," of their duties.

"It is the exhaustion of the priest who wears the smell of his sheep, but also smiles the smile of a father rejoicing in his children or grandchildren," Francis said, according to AP.