Pope Leo XIV will be the Catholic Church's 267th leader.
VATICAN CITY -- Robert Prevost of the United States has been named the new pope, the new head of the Catholic church.
Cardinals gathered to select their latest leader during a conclave.
White smoke poured out of the Sistine Chapel chimney Thursday at 6:07 p.m. local time, signaling that a pontiff had been elected to lead the Catholic Church.
(The Associated Press and ABC News contributed to this report.)
Cardinal Robert Francis Prevost has become the first-ever American elected as the leader of the Catholic Church -- now known by his pontifical name of Pope Leo XIV.
The 69-year-old, born on the Southside of Chicago, is seen as a diplomat of the church and was an important adviser to his predecessor, Pope Francis.
He became a front-runner to the papacy in the days before the conclave began, said the Rev. James Martin, a papal contributor to ABC News.
Leo emerged from the balcony of St. Peter's Basilica on Thursday evening to throngs of cheering crowds, following the signal of white smoke that emanated from the chimney atop the Sistine Chapel.
Leo is the fifth-most-popular name chosen by popes. Pope Leo XIV's full authority and jurisdiction begins immediately upon his acceptance of the office.
READ MORE | What we know about Leo XIV, the new American pope
Cardinal Robert Prevost, an American missionary who spent his career ministering in Peru and leads the Vatican's powerful office of bishops, was elected the first American pope in the 2,000-year history of the Catholic Church.
Prevost, 69, took the name Leo XIV.
A marching brass band in blue uniforms led a contingent of Swiss guards through the crowd to a central spot below the balcony, generating another huge roar from the crowd.
The Pontifical Swiss Guard is the official security force of the Vatican, and holds a ceremonial and a protective function.
And now more marching bands are celebrating the election of a new pope in a parade that includes large groups in military dress uniforms.
"Vivi il Papa!" erupts from the crowd whenever the music pauses.
That's where a cardinal will soon emerge to "to proclaim a new pope to Rome and to the world."
There is incredible excitement - the crowd is roaring, and some are shouting "hallelujah!"
Thousands of people have gathered in Vatican Square to witness the first appearance of the newly elected pope.
White smoke was released from the chimney atop the Sistine Chapel on Thursday evening, signifying that the 133 voting cardinals reached a two-thirds majority to chose the next leader of the Catholic Church.
Crowds cheered as the smoke emerged and the bells of St. Peter's Basilica rang.
The new pope is expected to address the crowd next to the iconic red velvet curtains lining the central balcony of the basilica.
