Pope Leo XIV calls for end to wars in Ukraine, Gaza

Cardinals preparing for the beginning of the conclave on Wednesday shared messages on social media before going into lockdown in the Vatican until the next pope is chosen.

Cardinal Natalio Chomali from Chile posted a video of himself hand washing his white shirt "to be impeccable for the conclave.”

American Cardinal Joseph Tobin posted prayers to X asking for support "as we gather in conclave to discern the Holy Spirit’s choice for the next Bishop of Rome," and later asking for “the Holy Spirit to guide us as we discern God’s will."

In a video message on a Filipino Catholic Facebook page, Filipino Cardinal Luis Antonio Tagle -- considered a frontrunner to be the next pope -- asked: "Who will you trust? People give their trust depending on their personal relationship. The only one you can trust is God. Give your trust to God who will direct you to the right path."

Another Filipino, Cardinal Pablo Virgilio David, wrote on his Facebook page, "SIGNING OFF STARTING TOMORROW EVENING.”

“How long before the white smoke comes out? That will be up to the Lord," David wrote.

-ABC News’ Camilla Alcini

The selection process for a new pope, which will commence on Wednesday, will begin when all cardinals under the age of 80 who are eligible to participate enter the secret conclave inside the Sistine Chapel to choose the next pontiff.

Father James Martin, a papal contributor to ABC News, said cardinals will be looking for "someone who is holy, someone who is a good evangelizer who can proclaim the gospel and someone who is a good manager."

Any baptized Catholic male is eligible to take Francis' place, but Miles Pattenden, historian of the Catholic Church at Oxford University, said Pietro Parolin, the cardinal secretary of state, and Luis Tagle, the archbishop of Manila in the Philippines, are the main front-runners.

-ABC News' Megan Forrester

Cardinal Timothy Dolan, the archbishop of New York, said in a post to X on Wednesday that he and the other North American cardinals will bring the “intentions” of regional Catholics to the conclave.

“Please keep us in your prayers,” Dolan wrote.

Cardinal Giovanni Battista Re, the dean of the College of Cardinals, reminded his fellow cardinals on Wednesday that they were about to undertake "an act of the highest human and ecclesial responsibility" in voting for a new pope.

"This is a human act for which every personal consideration must be set aside, keeping in mind and heart only the God of Jesus Christ and the good of the Church and of humanity," Re said in a homily during a Mass in St. Peter's Basilica.

But, he said, the election of a new pontiff also comes at a "difficult and complex turning point in history."

"Today's world expects much from the Church regarding the safeguarding of those fundamental human and spiritual values without which human coexistence will not be better nor bring good to future generations," Re said.