Francis said St Teresa had defended the unborn, sick and abandoned, and had shamed world leaders for the "crimes of poverty they themselves created".

Tens of thousands of pilgrims attended the canonisation in St Peter's Square.

Two apparent cures of sick people after Mother Teresa's death in 1997 have been attributed to her intercession.

In India, a special Mass was celebrated at the Missionaries of Charity, the order she founded in Kolkata (Calcutta).

Cardinal Angelo Amato read a brief biography of Mother Teresa's work, then asked the Pope to canonise her in the name of the Church.

Pope Francis responded: "We declare and define Blessed Teresa of Calcutta to be a saint and we enrol her among the saints, decreeing that she is to be venerated as such by the whole Church."

The Pope said Mother Teresa had spent her life "bowing down before those who were spent, left to die on the side of the road, seeing in them their God-given dignity".

He added: "She made her voice heard before the powers of the world, so that they might recognise their guilt for the crimes of poverty they themselves created." He then repeated: "The crimes of poverty they themselves created."

(BBC News)