The Latest: Trump gives Pope Martin Luther King Jr. books

The White House notes that Francis spoke about King and his civil rights legacy during his address to Congress in 2015.

The White House says the gift "honors Dr. King's hope, vision, and inspiration for generations to come."

Rome police say Greenpeace activists briefly projected the message "Planet Earth First" on the dome of St. Peter's Basilica on the eve of the pope's meeting with President Trump.

Police said in a statement Wednesday that the officers allowed the action to proceed for "a few moments" given the peaceable nature of the protest.

Pope Francis has made protection of the environment a keystone of his papacy, issuing a major encyclical on climate change.

Pope Francis gave the president copies of his three main teaching documents as parting gifts, as he typically does for visiting heads of state.

Some of the main themes contained in them contrast sharply with President Donald Trump's policies and campaign promises, particularly concerning approaches to the environment and income inequality.

Francis also shook hands with other members of the president's team, including former bodyguard Keith Schiller and social media director Dan Scavino.

Prior to the handshake, Trump walked toward the Saint Ambrose room, led by Gentlemen of his Holiness, which is a sort of honor guard of nobility.

The two men's often opposite worldviews collided head-on early last year, when Francis was sharply critical of Trump's campaign pledge to build an impenetrable wall on the Mexican border and his declaration that the United States should turn away Muslim immigrants and refugees.

Papal audiences usually last for about 20-30 minutes of private talks, followed by introductions of delegations, a photo and exchange of gifts.

[...] it could provide powerful imagery to Catholic voters back in the United States as well as the possibility for conflict between a president and a pope who have not often seen eye-to-eye.