Francis has publicly embraced Covid-19 vaccinations at a time when some religious conservatives have raised moral qualms with the vaccines — primarily due to remote links to abortion-derived cells during the development process. Earlier this week, the archbishop of the U.S. military said Catholic service members could refuse the mandatory vaccination on religious grounds, highlighting the ongoing split within the church.

At the same time, the pope's meeting with Biden, a devout churchgoer, comes amid an ongoing debate among Catholic leaders in the U.S. over whether to rebuke the president and other Catholic politicians for their support of abortion rights by denying them Communion. Last month, Francis declined to directly wade into the issue, but said that politics should stay separate from church practices and urged priests and ministers to "be pastors, and not go condemning."

Following the trip to Italy, Biden will head to the United Kingdom to attend the Conference of the Parties to the United Nations Framework Convention on Climate Change — shorthanded to COP26 — in Glasgow from Nov. 1-2.

It will mark Biden's second major trip to Europe as president. Over the summer he traveled across the Atlantic Ocean to attend meetings of the G-7, NATO and a U.S.-EU summit.