United States President Donald Trump, who had clashed with the pope on those issues, sat with the rows of foreign dignitaries on one side of Francis' coffin in the vast St. Peter's Square.

On the other side sat cardinals who will pick Francis' successor at a conclave next month, deciding if the new pope should continue with the late pontiff's push for a more open Church or cede to conservatives who want to return to a more traditional papacy.

The Argentine pope, who reigned for 12 years, died at the age of 88 on Monday after suffering a stroke.

"Rich in human warmth and deeply sensitive to today's challenges, Pope Francis truly shared the anxieties, sufferings and hopes of this time," said Italian Cardinal Giovanni Battista Re, who presided over the funeral Mass.

The Vatican estimated more than 250 000 people attended the ceremony, cramming the square and the roads around.

--Reuters--