VATICAN CITY (TNND) — The funeral Mass for Pope Francis is taking place in St. Peter's Square on Saturday, after more than 250,000 mourners visited St. Peter's Basilica over three days, paying their respects.

Francis died Monday at age 88 after suffering a cerebral stroke that put him into a coma and led to irreversible heart failure.

The pope's casket was closed and sealed Friday by Cardinal Kevin Farrell as part of the next steps in carefully orchestrated rites set off by the death of a pope.

The funeral began at 10 a.m. local time (4 a.m. EST) in St. Peter's Square with Cardinal Giovanni Battista Re, dean of the College of Cardinals, presiding over it.

World leaders, including President Donald Trump and Ukrainian President Volodymyr Zelenskyy, joined the public in saying farewell.

The Vatican said 164 delegations were confirmed, including 54 heads of state and 12 reigning sovereigns.

More than 2,500 police officers and 1,500 soldiers are providing security during the funeral, with officials expecting around 200,000 mourners in St. Peter's Square and up to 300,000 people along the 2-mile route from the Vatican to the pope's burial place.

Matteo Bruni, the Director of the Holy See Press Office, said the procession with the vehicle carrying the pope's body to St. Mary Major would leave from the Perugino Door to the Vatican and that it would not pass through St. Peter's Square.

"The procession toward St. Mary Major will take about half an hour, and the Pope’s coffin will be visible," he added. The burial will take place in private, according to the Vatican.

In keeping with Francis’s embrace of the marginalized, the Vatican said a group of poor and needy people will meet the pope’s coffin to pay homage to him when it arrives at St. Mary Major Basilica for burial.

In his final testament, the pope wrote, "The tomb should be in the ground; simple, without particular ornamentation, bearing only the inscription: Franciscus."

On Sunday afternoon, the Cardinals will go to the Marian Basilica, where they will pass through the Holy Door, visit Pope Francis' tomb, and then gather in the Pauline Chapel where the icon of Maria Salus Populi Romani is housed before participating in evening prayers.

The conclave won't start the work of electing a new pope until at least May 5, after nine days of public mourning.