The Mormon Church has deemed married same-sex couples to be apostates of the faith and their children ineligible for baptism in a reaffirmation of opposition to gay marriage months after endorsing fair housing and employment on the basis of sexual orientation.
The new policy was approved by Mormon leaders - the Council of the First Presidency and Quorum of the Twelve Apostles - to instruct local clergy how to proceed in light of the US Supreme Court's landmark ruling in June legalizing same-sex marriage and similar moves in other countries.
The Salt Lake City-based Church of Jesus Christ of Latter-day Saints, as the Mormon faith is formally known, claims more than 15 million members and 85,000 missionaries worldwide.
Mormon officials said church doctrine has long regarded marriage as a union solely reserved for a man and a woman. And while the church has staunchly opposed extending marriage rights to same-sex couples, it has welcomed celibate, single gay men and lesbians to the religion.
Under the policy approved on Thursday, same-sex marriage was added to the list of acts considered to be a renunciation of the Mormon faith and thus subject to church discipline, including excommunication.
The new policy also prohibits natural or adopted children of same-sex married couples from receiving a naming blessing or from being baptized or confirmed in the faith until they turn 18, leave their parents' home and personally disavow same-sex marriage or cohabitation.