Cardinals from 70 countries have gathered at the Vatican to elect a new Pope in the most diverse conclave in history.

The United States is home to 10 of the 133 cardinals eligible to vote for the next pope. That's more than any other nation except Italy, home to 17 of the electors who will gather at the Vatican’s Sistine Chapel on Wednesday for the conclave that will choose a successor to Pope Francis.

Leo XIV held his first Mass as pope in the Sistine Chapel on Friday, in what was a private service for the 132 voting cardinals who elected him as the 267th leader of the world’s 1.4 billion Catholics a day earlier.

Cardinal Blase Cupich, Archbishop of Chicago, said he expects Pope Leo XIV "feels an obligation," to speak to what he called the issues of the day, amid "real challenges globally."

Six are joining in their first papal conclave, and four others participated in the 2013 conclave that elected Pope Francis.

On "This Week," Cardinal Cupich said Pope Leo XIV may call for changes to the United States immigration system.

Leo gave a prepared address and then opened the floor to any cardinal who wanted to make a comment, a different format to what previous popes have done.

The next vote will take place at about 17:30 (16:30 BST) - no smoke will signal no decision has been reached, white smoke that there is a new pope