At the start of his address, Pope Leo extended his wishes for peace and good in the new year and offered a special greeting to the president of the Italian Republic, Sergio Mattarella.
After the Angelus prayer, the pope said Jan. 1 has been marked as the World Day of Peace since 1968 at the initiative of Pope St. Paul VI.
Reflecting on the meaning of the day, Pope Leo referred to the words that came to him after his election as bishop of Rome: "Peace be with you all."
"This peace," the pope said, "is unarmed and disarming. It comes from God; it is a gift of his unconditional love, and it is entrusted to our responsibility."
He also emphasized that peace is not something imposed by force, but a gift that needs personal conversion and choices in daily life.
Calling on Christians and all people of goodwill, Pope Leo urged them to begin immediately.
"With Christ’s grace," he said, "let us start today to build a year of peace, disarming our hearts and refraining from all violence."
The pope acknowledged that efforts to build peace are already underway across the world and expressed appreciation for individuals and organizations dedicated to ending conflict and promoting dialogue.
In line with the peacekeeping theme, he highlighted a national peace march held Dec. 31 in Catania, Italy, and mentioned another organized by members of the Community of Sant’Egidio, known for its international peace initiatives.
Pope Leo also welcomed students and teachers from Richland, New Jersey, who were in the square watching.
At the end of the address, the pope spoke about the 800th anniversary of the death of St. Francis of Assisi, a figure also closely associated with peace.
He closed with the saint’s biblical blessing: "The Lord bless you and keep you; the Lord make his face shine upon you and be gracious to you; the Lord lift his countenance upon you and give you peace."
Pope Leo ended by entrusting the new year to Mary, the Mother of God, asking that she guide humanity on its journey in the new year.