VATICAN CITY -- Pope Francis, the newly elected leader of the Catholic Church, took part Thursday in his first mass, inside the Sistine Chapel.

The Vatican says Cardinal Jorge Mario Bergoglio will be officially installed as Pope on Tuesday.

He started his first full day as pope praying at Saint Mary Major Basilica in Rome.

The 76-year-old Argentine received the required two-thirds majority vote from his fellow cardinals on the second day of the conclave.

He was greeted by roaring crowds as he emerged on the balcony at St. Peter's Basilica after the announcement.

Bells rang and thousands cheered in St. Peter's Square.

The new pope addressed the faithful, led them in prayer and asked them to pray for the lord to bless him, adding, "It's a journey of brotherhood and trust among us. Let us pray always for us, let us pray, always for us, one for the other, each one for one another. Let us pray for the entire world."

Francis has already spoken with his predecessor, Pope Emeritus Benedict XVI.

Pope Francis becomes the first pope from the Americas.

The last non-European pope was Syria's Gregory III, who served until the year 741.

Francis will now have the job of leading the world's 1.2 billion Roman Catholics.

New York Cardinal Timothy Dolan issued a statement after the announcement calling the election a great milestone for the church, saying intense prayer surrounded the election of Pope Francis.

Speaking with reporters, Dolan was asked if he felt a sense of relief after the vote, since rumors had surfaced he might be selected as pope.

"I wouldn't say there's a sense of relief because I didn't take those things seriously. I'd like to say this especially to the New York press - I told you so," Dolan said.

Pope Francis is from Buenos Aires and of Italian descent.

Francis was ordained in 1969, appointed Bishop in 1992 and Cardinal in 2001.

He is the first Jesuit pope, and holds many views in line with the church, opposing abortion and same sex marriage.

But he has displayed sympathy for people with drug additions and AIDS, and considers social outreach essential to the church.

As cardinal, he refused many luxuries associated with the job, living in an apartment rather than the archbishop's palace.

He often rode the bus to work and cooked his own meals.

Francis was widely believed to have finished second when Pope Benedict was elected in 2005.

The name Francis he chose as his papal title was inspired by Saint Francis of Assisi, known as a symbol of peace, poverty and simplicity.