The Vatican said on Monday that priests and other Catholic Church ministers cannot bless same-sex unions and that such blessings are "not licit" if carried out.
The Vatican's doctrinal office, the Congregation for the Doctrine of the Faith (CDF), issued the ruling in response to questions and moves in some parishes to impart such blessings as a sign of welcome to gay Catholics since the Church does not permit homosexual marriage.
Pope Francis approved the response, the CDF said, adding that it was "not intended to be a form of unjust discrimination, but rather a reminder of the truth of the liturgical rite".
It said such blessings were not permissible even though they were "motivated by a sincere desire to welcome and accompany homosexual persons" and help them grow in the faith.
The CDF note said that since marriage between a man and a woman was a sacrament and blessings are related to the sacrament of marriage, they could not be extended to same-sex couples.
"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," it said.