By Philip Pullella

VATICAN CITY (Reuters) - They may be the most powerful people on earth, but for the seating arrangement at Pope Francis' funeral on Saturday, all foreign leaders will play second fiddle to the Argentines and Italians and surrender to the whims of the French alphabet.

About 130 foreign delegations had so far expressed their desire to attend the funeral, the Vatican said on Friday, and more were expected to do so throughout the day. Those include around 50 heads of state who have been confirmed as attending, among them U.S. President Donald Trump and 10 reigning monarchs. 

Apart from the VIPs, hundreds of thousands of people are expected to attend the funeral in St. Peter's Square, which starts at 10 a.m. (0800 GMT) on Saturday. Italian police have laid on one of the most complex security operations in decades.

The official delegations will sit at a section to the right of the altar at the top of the steps leading toward St. Peter's Basilica.

Pride of place goes to Argentina, Francis' native country, whose president, Javier Milei, will sit in the front row.

Milei, a maverick right-wing libertarian, had heaped insults on Francis while he was campaigning in 2023, calling him an "imbecile who defends social justice". But the president shifted his tone after he took office that year.

Next comes Italy, the country that surrounds the Vatican and which agreed in 1929 to recognise its sovereignty as the world's smallest state. It gets the second-best seats in the VIP section also because the pope is bishop of Rome and primate of the Catholic bishops of Italy.

That is when the alphabet in French – still considered the language of diplomacy – kicks in for the other delegations. The countries following Italy are ordered according to their names in French and not in their native languages.

So, it is Etats Unis and not United States, Allemagne instead of Deutschland (Germany), and Pays-Bas instead of Nederland (The Netherlands).

Royalty will take precedence. Reigning monarchs -- expected to include royalty such as the kings and queens of Spain and Belgium and Prince Albert of Monaco -- will be seated in front of other heads of state.

Vatican spokesman Matteo Bruni said on Friday that no distinction would be made between Catholic and non-Catholic royalty for the seating order.

After the royals come the remaining heads of state. Trump, who attracted criticism from Francis because of his immigration policies, will sit ahead of many other leaders because Etats Unis begins with an 'E'.

That alphabetic logic means that Trump - currently engaged in trying to get a peace deal in the war in Ukraine - will not be sitting near Ukrainian President Volodymyr Zelenskiy.

Former U.S. President Joe Biden, who has been the target of constant criticism by Trump, is attending the funeral, but will not be part of the official U.S. delegation, a diplomatic source said. This means Biden, a lifelong Catholic, should be sitting further back, with other VIPs.

(Reporting by Philip Pullella; Additional reporting by Joshua McElwee; Editing by Crispian Balmer and Frances Kerry)