Catholic clergy cannot bless same-sex unions, the Vatican has confirmed.
The Congregation for the Doctrine of the Faith said it was not possible to impart a blessing on sexual relationships beyond a marriage between a man and a woman because they were "not ordered to the Creator's plan".
The written clarification was issued on Monday in response to a question asking whether the Church has the power to give blessings to same-sex unions.
In a note explaining its answer, the Vatican said that although some ecclesial contexts are pushing forward with blessings for same-sex unions out of a "sincere desire to welcome and accompany homosexual persons", in the Catholic Church these "cannot be considered licit" because they would be seen to "approve and encourage a choice and a way of life that cannot be recognized as objectively ordered to the revealed plans of God".
The response explained that in order for a blessing to be imparted by the Church, it "is necessary that what is blessed be objectively and positively ordered to receive and express grace, according to the designs of God inscribed in creation, and fully revealed by Christ the Lord".
"Therefore, only those realities which are in themselves ordered to serve those ends are congruent with the essence of the blessing imparted by the Church," it said.
"For this reason, it is not licit to impart a blessing on relationships, or partnerships, even stable, that involve sexual activity outside of marriage (i.e., outside the indissoluble union of a man and a woman open in itself to the transmission of life), as is the case of the unions between persons of the same sex.
"The presence in such relationships of positive elements, which are in themselves to be valued and appreciated, cannot justify these relationships and render them legitimate objects of an ecclesial blessing, since the positive elements exist within the context of a union not ordered to the Creator's plan."
It goes on to quote Pope Francis' 2016 apostolic exhortation Amoris laetitia (The Joy of Love), which states that "there are absolutely no grounds for considering homosexual unions to be in any way similar or even remotely analogous to God's plan for marriage and family".
The response also clarifies that a declaration on the "unlawfulness" of blessing same-sex unions is not intended to be "a form of unjust discrimination, but rather a reminder of the truth of the liturgical rite and of the very nature of the sacramentals, as the Church understands them".
It calls on pastors and churches to welcome gay people "with respect and sensitivity" and "to find the most appropriate ways, consistent with Church teaching, to proclaim to them the Gospel in its fullness".
"At the same time, they should recognize the genuine nearness of the Church – which prays for them, accompanies them and shares their journey of Christian faith – and receive the teachings with sincere openness," it says.
It concludes: "At the same time, the Church recalls that God Himself never ceases to bless each of His pilgrim children in this world ... But he does not and cannot bless sin: he blesses sinful man, so that he may recognize that he is part of his plan of love and allow himself to be changed by him ... For the above mentioned reasons, the Church does not have, and cannot have, the power to bless unions of persons of the same sex in the sense intended above."