VATICAN CITY — Pope Francis has signed off on the miracle needed to make Mother Teresa a saint, giving the nun who cared for the poorest of the poor one of the Catholic Church’s highest honors just two decades after her death.

The Vatican said Friday that Francis approved a decree attributing a miracle to Mother Teresa’s intercession during an audience with the head of the Vatican’s saint-making office on Thursday, his 79th birthday.

No date was set for the canonization, but Italian media have speculated that the ceremony will take place in the first week of September — to coincide with the anniversary of her death, and during Francis’ Holy Year of Mercy.

“This is fantastic news. We are very happy,” said Sunita Kumar, a spokeswoman for the Missionaries of Charity in the eastern city of Kolkata (earlier called Calcutta), where Mother Teresa lived and worked.