Vatican City, Holy See (AFP)—Pope Francis, champion of the poor and the Church’s first Latin American leader, will be honoured Saturday with a funeral attended by world leaders and tens of thousands of Catholic faithful.

The Argentine pontiff, who died on Monday aged 88, sought to create a more open-minded Church during his 12-year papacy, and many emotional tributes have been made — with 250,000 people paying respects at his coffin in St Peter’s Basilica.

US President Donald Trump is among more than 50 heads of state due to attend the mass in St Peter’s Square at the Vatican, set to start at 10:00 am (0800 GMT).

Italian and Vatican authorities have mounted a major security operation for the event, expected to draw up to 200,000 people.

A no-fly zone is in place, fighter jets are on standby and snipers will be positioned on roofs surrounding the tiny city state.

During the three days of his coffin lying-in-state, many people queued for hours to catch a brief glimpse of a man known for his human touch, jokes and defence of the vulnerable.

“He helped a lot of people, he noticed a lot of people that weren’t noticeable before,” Sofiia Popkova, a 19-year-old from Kyrgyzstan, told AFP after a “breathtaking” experience seeing Francis’s body.

The funeral sets off the first of nine days of official Vatican mourning for Francis, who took over following the resignation of Pope Benedict XVI in 2013.

After the mourning, cardinals will gather for the conclave to elect a new pope to lead the world’s 1.4 billion Catholics.