Pope Francis has declined to confirm or deny claims by the Vatican's retired ambassador to the United States that he knew in 2013 about sexual misconduct allegations against the former archbishop of Washington.
Francis said the 11-page text by Archbishop Carlo Maria Vigano "speaks for itself" and that he would not comment on it.
Francis was asked by a US reporter if Mr Vigano's claims that the two discussed the Theodore McCarrick allegations in 2013 were true.
The pope was also asked about Mr Vigano's claims that McCarrick was already under sanction at the time, but that Francis rehabilitated him. He said he had read Mr Vigano'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 Mr Vigano's text on Sunday as the pope wrapped up a two-day visit to Ireland dominated by the clerical sex abuse scandal.
Mr Vigano (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 US 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 when he was 11 years old, and several former seminarians have said McCarrick abused and harassed them when they were in seminary.
Mr Vigano's letter identifies by name the Vatican cardinals and US archbishops who were informed about the McCarrick affair. He said documents backing up his version of events are in Vatican archives.
The Vatican's ambassador to the US from 2011 to 2016, Mr Vigano said his two immediate predecessors "did not fail" to inform the Holy See about accusations against McCarrick, starting in 2000.
He said Pope Benedict XVI eventually sanctioned McCarrick in 2009 or 2010 to a lifetime of penance and prayer.
He said Francis asked him about McCarrick when they met on June 23, 2013, three months after Francis was elected.
Mr Vigano wrote that he told Francis "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, Mr Vigano wrote, he was surprised to find that McCarrick had started travelling on missions on behalf of the church, including to China.
McCarrick was also one of the Vatican's intermediaries in the US-Cuba talks in 2014.