ABOARD THE PAPAL PLANE (AP) — Pope Francis declined Sunday (Aug. 26) to confirm or deny claims by the Vatican’s retired ambassador to the United States that Francis knew in 2013 about sexual misconduct allegations against the former archbishop of Washington, Theodore McCarrick, but rehabilitated him anyway.

Francis said the 11-page text by Archbishop Carlo Maria Viganò, which reads in part like a homophobic attack on Francis and his allies, “speaks for itself” and that he wouldn’t comment on it.

RELATED: Letter: Vatican knew about disgraced archbishop’s behavior

Francis was asked by a U.S. reporter during an airborne news conference Sunday if Viganò’s claims that the two discussed the McCarrick allegations in 2013 were true. Francis was also asked about Viganò’s claims that McCarrick was already under sanction at the time but that Francis rehabilitated him.

Francis said he had read Viganò’s document and trusted journalists to judge for themselves.

“It’s an act of trust,” he said. “I won’t say a word about it.”

The National Catholic Register and another conservative site, LifeSiteNews, published Viganò’s text Sunday as the pope wrapped up a two-day visit to Ireland dominated by the clerical sex abuse scandal.

Viganò, 77, a conservative whose hard-line anti-gay views are well-known, urged the reformist pope to resign over what he called Francis’ own culpability in covering up McCarrick’s crimes.

Francis accepted McCarrick’s resignation as cardinal last month, after a U.S. church investigation determined that an accusation he had sexually abused a minor was credible.

Since then, another man has come forward to say McCarrick began molesting him starting when he was 11, and several former seminarians have said McCarrick abused and harassed them when they were in seminary. The accusations have created a crisis of confidence in the U.S. and Vatican hierarchy, because it was apparently an open secret that McCarrick regularly invited seminarians to his New Jersey beach house, and into his bed.

Coupled with the devastating allegations of sex abuse and cover-up in a recent Pennsylvania grand jury report — which found that 300 priests had abused more than 1,000 children over 70 years in six dioceses — the scandal has led to calls for heads to roll and for a full Vatican investigation into who knew what and when about McCarrick.

Viganò apparently sought to answer some of those questions. His letter identifies by name the Vatican cardinals and U.S. archbishops who were informed about the McCarrick affair, an unthinkable expose for a Vatican diplomat to make. He said documents backing up his version of events are in Vatican archives.

The Vatican’s ambassador to the U.S. from 2011 to 2016, Viganò said his two immediate predecessors “did not fail” to inform the Holy See about accusations against McCarrick, starting in 2000. Viganò said he himself sent at least two memos on McCarrick.

Viganò said Pope Benedict XVI eventually sanctioned McCarrick in 2009 or 2010 to a lifetime of penance and prayer, and to no longer celebrate Mass in public or travel.

Viganò said Francis asked him about McCarrick when they met on June 23, 2013, at the Vatican’s Santa Marta hotel where the pope lives, three months after Francis was elected pope.

Viganò wrote that he told Francis: “Holy Father, I don’t know if you know Cardinal McCarrick, but if you ask the Congregation of Bishops, there is a dossier this thick about him. He corrupted generations of seminarians and priests, and Pope Benedict ordered him to withdraw to a life of prayer and penance.”

Soon thereafter, Viganò wrote, he was surprised to find that McCarrick had started traveling on missions on behalf of the church, including to China. McCarrick was also one of the Vatican’s intermediaries in the U.S.-Cuba talks in 2014.

Viganò’s claim that McCarrick had been ordered by Benedict to stay out of public ministry and retire to a lifetime of prayer is somewhat disputed, given that McCarrick enjoyed a fairly public retirement. But Viganò insisted the sanctions had been imposed, and said a former counselor in the embassy at the time was “prepared to testify” about the “stormy” meeting when McCarrick was informed of them.

Barry Coburn, McCarrick’s civil attorney, said the allegations in the Viganò letter are “serious.”

“Archbishop McCarrick, like any other person, has a right to due process. He looks forward to invoking that right at the appropriate time,” he said in a statement.

The letter also contains a lengthy diatribe about homosexuals and liberals in the Catholic Church. It often reads like an ideological manifesto, naming all of Francis’ known supporters in the U.S. hierarchy as being complicit in a cover-up of McCarrick’s misdeeds.

“Now that the corruption has reached the very top of the church’s hierarchy, my conscience dictates that I reveal those truths regarding the heart-breaking case of the archbishop emeritus of Washington,” Viganò wrote.

Viganò, however, also has had his own problems with allegations of cover-up, and he and Francis had a major dust-up during Francis’ 2015 visit to the U.S., which Viganò organized.

In that incident, a leading U.S. opponent of gay marriage, Kim Davis, was among those invited to meet with the pope at Viganò’s Washington residence. Francis was so enraged that Davis’ supporters had leaked word of the meeting that the Vatican subsequently insisted he only held one private audience while there: with one of his former students, a gay man and his partner.

The cover-up accusation, which Viganò denied, concerned allegations that he tried to quash an investigation into the former archbishop of St. Paul-Minneapolis, Minn., John Nienstedt, who was accused of misconduct with adult seminarians.

In 2016, the National Catholic Reporter said Viganò allegedly ordered the investigation wrapped up and a piece of evidence destroyed. The report cited a 2014 memo from a diocesan official that was unsealed after the conclusion of a criminal investigation into the archdiocese. No charges were filed.

In a statement provided Sunday to the AP about the Nienstedt case, Viganò said a Vatican investigation of the allegation found no wrongdoing on his part.

He said the allegation that he destroyed evidence was false and that his efforts to have the archdiocese correct the record have been met with silence.

Nienstedt was forced to resign in 2015 over complaints about his handling of sex abuse cases.

Viganò’s name also made headlines during the 2012 “Vatileaks” scandal, when some of his letters were published. In them, he begged not to be transferred to the Vatican Embassy in Washington from the administration of the Vatican City State.

He claimed he was being punished for having exposed corruption in the Vatican. The letters showed a clash with Benedict’s No. 2, Cardinal Tarcisio Bertone, who is also a target of Viganò’s McCarrick missive.

The document’s authenticity was confirmed to The Associated Press by an Italian journalist, Marco Tosatti, who said he was with Viganò when the archbishop wrote it Wednesday.

“He was very emotional and upset at the end the effort,” Tosatti told AP, adding that Viganò left Tosatti’s home afterward without saying where he was going.