Royalty, world leaders to join multitude of mourners

The Pope's coffin is sealed ahead of his funeral

Royalty, presidents, prime ministers and a legion of faithful will pay their last respects to Pope Francis at a funeral Mass in St Peter's Square to honour his sometimes turbulent papacy.

Among those attending on Saturday from more than 150 countries will be United States President Donald Trump, who clashed with Francis on numerous occasions over their starkly contrasting positions on immigration.

The Argentine pope, who led the Catholic Church since 2013, died on Monday in his rooms at the Vatican's Santa Marta guesthouse after suffering a stroke as he was recuperating from weeks of double pneumonia. He was 88.

Over the past three days, an estimated 250,000 people filed past his body, which had been laid out in a coffin before the altar of the cavernous, 16th century St Peter's Basilica in the Vatican.

Soon after 7pm on Friday the Vatican ended a television broadcast of the visits that had been running nearly continuously.

A formal summary of Francis' papacy, written in Latin, was placed in the coffin casket as it was sealed. It described him as a "beloved and simple pastor" who left "a marvellous testimony of humanity, of a holy life and of universal fatherhood."

Among the last visitors were French President Emmanuel Macron and his wife Brigitte, who stood together at the side of the casket for a few moments. He bowed his head; she made the sign of the cross.

Long queues snaked around St Peter's Square and the surrounding roads all day on Friday. Some waited hours for the chance to spend a few minutes inside the basilica and pay their respects.

"It's a very strong feeling (to be here)," said Patricio Castriota, a visitor from Argentina, the Pope's homeland. "This farewell was very sad, but I thank God that I was able to see him".

"He's the only pope we've had who came from South America, a pope who had many good intentions for the Catholic Church," said Castriota. "He cleaned up (a lot) of the bad, maybe not all of it, but he tried."

Outdoor funeral

The coffin will be carried through the main doors on Saturday for the outdoor funeral, which starts at 10am (8pm NZ time), with massed ranks of foreign dignitaries to one side of the stone colonnade, facing hundreds of red-hated cardinals on opposite banks of seats.

Alongside Trump will be the presidents of Argentina, France, Gabon, Germany, Italy, the Philippines, Poland and Ukraine, together with the prime ministers of Britain and New Zealand, and many European royals.

The Vatican says some 250,000 mourners will fill the vast, cobbled esplanade and main access route to the basilica to follow the ceremony, which will be presided over by Cardinal Giovanni Battista Re, a 91-year-old Italian prelate.

Authorities began ramping up security ahead of the ceremony, with snipers on rooftops, drones watching from the sky and an army device readied to neutralise hostile flying objects.

The heart of Rome is expected to be closed to traffic on Saturday to allow a funeral motorcade carrying the Pope's remains to make its way slowly to the Basilica of Santa Maria Maggiore (St Mary Major), where Francis, in a break from tradition, asked to be buried instead of St Peter's. 

Crowds were expected along the route, which will pass by many of Rome's famed monuments, including the Colosseum.

The Pope's tomb will be in a niche in a side aisle of the basilica, with just the word "Franciscus", his name in Latin, engraved on the marble.

Break with tradition

The first non-European pope for almost 13 centuries, Francis battled to reshape the Roman Catholic Church during his 12-year reign, siding with the poor and marginalised, while challenging wealthy nations to help migrants and reverse climate change.

"Francis left everyone a wonderful testimony of humanity, of a holy life and of universal fatherhood," said a formal summary of his papacy, written in Latin, and placed next to his body.

Traditionalists pushed back at his efforts to make the Church more transparent, while his pleas for an end to conflict, divisions and rampant capitalism often fell on deaf ears.

Francis shunned much of the pomp and privilege usually associated with the papacy during his reign, and will carry that desire for greater simplicity into his funeral, having re-written the elaborate, book-long funeral rites used previously.

Whereas Pope John Paul II's funeral in 2005 lasted three hours, the service on Saturday is due to take 90 minutes.

Francis also opted to forego a centuries-old practice of burying popes in three interlocking caskets made of cypress, lead and oak. Instead, he has been placed in a single, zinc-lined wooden coffin. 

In a further break with tradition, he will be the first pope to be buried outside the Vatican in more than a century, preferring Rome's Basilica of St Mary Major, some 4km from St Peter's, as his final resting place.

His tomb has just "Franciscus", his name in Latin, inscribed on the top. A reproduction of the simple, iron-plated cross he used to wear around his neck hangs above the marble slab.

Italy has closed the airspace over the city and called in extra forces, with anti-aircraft missiles and patrol boats guarding the event in one of the biggest security operations the country has seen since the funeral of John Paul II.

As soon as Francis is buried, attention will switch to who might succeed him.

The secretive conclave to elect a successor is unlikely to begin before May 6, and might not start for several days after that, giving cardinals time to hold regular meetings beforehand to sum each other up and assess the state of the Church, beset by financial problems and ideological divisions.