The Vatican has excommunicated controversial Italian Archbishop Carlo Maria Vigano, its former ambassador to the U.S. from 2011 to 2016.

Vigano, an ultra-conservative and a strident critic of Pope Francis, was found guilty of schism and was excommunicated, the Vatican’s doctrinal office said in a statement Friday. The Catholic Church considers schisms in the church as a dangerous matter because they can threaten the unity of the church.

Vigano has declared several times in recent years that he does not recognize the legitimacy of Pope Francis or the Second Vatican Council, a series of meetings in the 1960s that modernized the church.

Vigano has also taken exception to what he perceives as the pope’s liberal stance on issues and in a statement on the X social media platform last month, Vigano accused Francis of representing an “inclusive, immigrationist, eco-sustainable and gay-friendly" church, that has strayed far from the tenets of the Catholic Church.

An article on the website vaticannews.va about the church’s move against Vigano says that "excommunication is considered a 'medicinal' penalty that aims at inviting the offender to repentance ... there is always the hope that the subject of excommunication will return to communion."

Vigano had the opportunity to defend himself in the proceedings against him at the Vatican but did not. However, a public defender was appointed for the absent cleric "who undertook Vigano’s defense, according to the norms of law," vaticannews.va reported.

Vigano has not been seen in public since 2018, after he accused Pope Francis of knowing about and ignoring the sexual misconduct of U.S. Cardinal Theodore McCarrick. His accusation came when the Church was in the middle of a sexual abuse scandal with allegations that both children and adults had been abused by priests for decades without any repercussions for the offending clerics or the clerics who knew about the offensives but did nothing.

The Vatican has rejected all of Vigano’s cover-up accusations about Pope Francis.

While Vigano has not made any public appearances, he continues to post communications on X.

Some information for this report was provided by The Associated Press and Reuters.