Final mourners were in a queue for their last chance to see Pope Francis's remains - as a UK cardinal predicted the funeral will be a "masterpiece" in stage managing "big egos" as world leaders fly in to pay their respects.
US President Donald Trump is among those due to attend the requiem mass for the late pontiff, joining dignitaries from across the globe.
Tens of thousands of members of the public have queued and filed past Francis's open coffin in St Peter's Basilica, during its three-day lying-in-state which will end on Friday evening.
Funeral preparations are under way, with an altar in place and seats set out for cardinals as well as world leaders.
Italian police are on the ground managing crowds, while scaffolding has been erected to provide international media with the best vantage points overlooking the square, for a funeral expected to be watched by people around the world.
Vast crowds are expected to gather ahead of Saturday's funeral in St Peter's Square, which will see the highest-ranking members of the Catholic Church and major political leaders come together to bid a final farewell to the 88-year-old Pope.
Also on the list to attend are UK Prime Minister Sir Keir Starmer, the Prince of Wales on behalf of the King, French President Emmanuel Macron, Ukrainian President Volodymyr Zelensky, Irish premier Micheal Martin and the nation's President Michael D Higgins.
President Higgins was among those to visit the basilica on Friday, and was pictured alongside his wife Sabina as they paid their respects.
The queue will close to the public at 6pm local time, with viewings expected to end at 7pm.
Some 150,000 have passed by Francis's coffin in the past three days.
An emergency alert rang out on phones in Vatican City on Friday, with a warning from the civil protection department that public access to St Peter's Square would close at 5pm the same day.
Meanwhile, the leader of Catholics in England and Wales, Cardinal Vincent Nichols, said organisers of what will be an enormous gathering of well-known names "are geniuses at dealing with these big events".
In an interview in Rome, the Archbishop of Westminster said the funeral will be "without a doubt another masterpiece of stage management when you consider those state leaders who have high opinions of their importance".
He added: "In the past, I've seen it here over and over again that the combination of Rome and the Holy See, they actually are geniuses at dealing with these big events.
"I think they've been doing it since the emperors ruled Rome - that they know how to deal with big egos.
"And I think every leader of a nation that comes here on Saturday, will go home reasonably content."
