Pope Leo XIV on Sunday urged more than a million Catholic youths to “spread your enthusiasm and the witness of your faith” when they return home to some 150 countries, during a Mass closing a weeklong encounter with the next generation of faithful.

Pope Leo XIV addressed a massive crowd of about one million people at a Catholic youth vigil on Saturday, the Vatican said. It’s the pontiff’s biggest event since his election in May. NBC News’ Claudio Lavanga reports from Rome.

Young people from more than 146 countries, some wearing colourful bandanas to ward off the hot summer sun, were pressed against fences in the Tor Vergata field as Leo toured the crowd in his white popemobile in late afternoon.