Watch in full: Pope Leo XIV holds inaugural mass in front of thousands at St Peter’s Square

Pope Leo XIV delivered his inaugural mass in the Vatican’s St. Peter's Square on Sunday, 18 May, in front of world leaders and thousands of well-wishers.

Catholic convert JD Vance, who clashed with Francis over the Trump administration's hard-line immigration policies, led a US delegation alongside secretary of state Marco Rubio, who is also Catholic.

Volodymyr Zelensky, his wife, Olena Zelenska, his chief adviser Andriy Yermak and foreign minister Andriy Sybiha were also in attendance.

Ahead of the formal ceremony, the pontiff greeted enthusiastic crowds, estimated to reach around 150,000 people today, during his first ride in the open-top popemobile.

Faithful held flags and cheered “Viva il Papa!” as Leo, the first American pope, waved back to them as he looped slowly through the square.

Leo replaces Pope Francis, from Argentina, who died on 21 April after leading the Church for 12 years.

During the inauguration mass, the pontiff received two signs of his pontificate — the "pallium" and the fisherman's ring, marking his role as successor of Peter.