US President Joe Biden's motorcade, with two similar vehicles with US and Vatican flags, snaked through Vatican City on Friday to bring the US leader to his fourth meeting with Pope Francis.
The world's two most notable Roman Catholics plan to discuss the COVID-19 pandemic, climate change and poverty.
After sitting for a moment in his bullet-proof, armor-plated vehicle, known as "The Beast" – Biden got out and shook hands with several Vatican officials before being escorted into the Apostolic Palace with First Lady Jill Biden following.
The president takes pride in his Catholic faith, using it as moral guidepost to shape many of his social and economic policies.
Biden wears a rosary and frequently attends Mass, yet his support of abortion rights and same-sex marriage has put him at odds with many U.S. bishops, some of whom have suggested he should be denied Communion.
As only the second Catholic president after John F. Kennedy, Biden has made his audience with the pope a clear priority.
Biden and the pope have previously met three times but this will be their first encounter since Biden became president, and the first since 2016.
The Vatican has decided to not broadcast the meeting between the two, despite the objections of journalists.