The Vatican decreed Monday that the Catholic Church cannot bless same-sex unions since God "cannot bless sin."

The Vatican’s orthodoxy office, the Congregation for the Doctrine of the Faith, issued the decision in a formal response to a question about whether Catholic clergy can bless gay unions.

The answer, which came in the form of a two-page explanation, published in seven languages and approved by Pope Francis, was "negative".

The decree distinguished between the church’s welcoming and blessing of gay people, which it upheld, but not their unions since any such sacramental recognition could be confused with marriage.