Obama will meet with Pope Francis at the Vatican on March 27th to discuss poverty and inequality, the White House said in a statement. While in Rome he will also meet Letta and Napolitano.
The visit is part of a wider Europe trip, which includes a US-EU summit in Brussels on March 26th, when Obama will meet with Herman Van Rompuy, president of the European Council, and European Commission President José Manuel Barroso.
Source: http://www.thelocal.it