Roman Catholic leaders from around the world are gathering at the Vatican for a synod, or meeting, to address issues facing the church, including whether to allow women to become deacons.

In a letter to conservative cardinals, the pope suggested that such blessings for same-sex unions could be studied if they didn't confuse the blessing with sacramental marriage.

Catholic women's groups that have long criticized the Vatican for treating women as second-class citizens immediately praised the move as historic in the 2,000-year life of the church.

The doctrine, with origins in the 15th century, was invoked as a legal and religious standing by Europeans who "discovered" new lands and violently seized it from people who had been living there.

The leader of the world's 1.3 billion Catholics has steered his church leftward after more than two decades of conservative leadership. Opposition within the Vatican is fierce.

The Vatican opened a file on the disappearance of a teenage girl months after a new Netflix documentary aired on the case and weeks after her family asked the Italian Parliament to take up the cause.

Pope Francis has revealed in an interview published Sunday that shortly after being elected pontiff in 2013 he wrote a resignation letter in case medical problems impede him from doing his duties.

Pope Francis began a visit to Canada on Sunday to apologize to Indigenous peoples for abuses at residential schools, part of the the Catholic Church's efforts to reconcile with Native communities.

Francis says individuals have a responsibility to care for themselves "and this translates into respect for the health of those around us."

President Biden's meeting at the Vatican with the pope is one of several gatherings scheduled with global leaders over the next week.

The pope and the president share liberal stances on climate change and economic disparity. A theology scholar argues U.S. Catholic Church leadership is increasingly allied with the political right.

The Vatican said it's permitted to get COVID-19 vaccines due to the "grave danger" of the pandemic, even if scientists used "cell lines from aborted fetuses in their research and production process."

Wilton Gregory, the archbishop of Washington, D.C., is among 13 church leaders elevated to cardinal at a ceremony at the Vatican on Saturday.

A 28-year-old priest is charged with sexually abusing an altar boy over a five-year period in a Vatican City youth seminary. Another priest, the former rector, is charged with covering up the abuse.

The Vatican has long maintained that Pope Pius XII did everything he could to save Jewish lives, but newly unearthed papers have renewed accusations of complicit silence against him.