Hassan Rouhani has arrived in Rome on the first European visit by an Iranian president in almost two decades, following implementation of a landmark deal on curbing Iran's nuclear activities.
Mr Rouhani, eager for foreign investment after the lifting of international sanctions, is on a four-day trip to France and Italy.
The trip was originally planned for November but postponed by the attacks in Paris.
He met first with Italian president Sergio Matterella and is scheduled to meet Italian prime minister Matteo Renzi and Pope Francis at the Vatican.
In France, he is to be welcomed by French president Francois Hollande.
Europe was Iran's largest trading partner before the sanctions, and business and trade deals are expected.