Pope Francis reportedly opened the door for Catholic priests to bless same-sex unions on Monday.
The Vatican on Monday published a letter Francis wrote to the cardinals on 11 July after receiving a list of five questions from them a day earlier.
In it, Francis suggests that such blessings could be studied if they did not confuse the blessing with sacramental marriage.
The pope was responding to five conservative cardinals who challenged him to affirm church teaching on homosexuality ahead of a big meeting where LGBTQ+ Catholics are on the agenda.
The Vatican holds that marriage is an indissoluble union between man and woman. As a result, it has long opposed gay marriage.