VATICAN CITY, Holy See (AFP) — Pope Leo XIV is set to create seven new saints Sunday, including the first from Papua New Guinea, an archbishop killed in the Armenian genocide and a Venezuelan "doctor of the poor."

Also set to be canonized in the solemn ceremony in St. Peter's Square on World Mission Day are three nuns who dedicated their lives to the poor and sick, and former Satanic priest Bartolo Longo.

Born in 1841, the Italian lawyer subsequently rejoined the Catholic faith and went on to found the Pontifical Shrine of the Blessed Virgin of the Rosary of Pompeii.

The canonization will be the second for the American pope since he was made leader of the Catholic Church on 8 May.

Last month, he proclaimed as saints Italians Carlo Acutis — a teenager dubbed "God's Influencer" who spread the faith online before his death at age 15 in 2006 — and Pier Giorgio Frassati, considered a model of charity who died in 1925, aged 24.

Canonization is the final step towards sainthood in the Catholic Church, following beatification.

Three conditions are required — most crucially that the individual has performed at least two miracles. He or she must be deceased for at least five years and have led an exemplary Christian life.

Those to be proclaimed saints Sunday are Peter To Rot, a lay catechist from Papua New Guinea killed during the Japanese occupation during World War II, Armenian bishop Ignazio Choukrallah Maloyan killed by Turkish forces in 1915, and Venezuela's Jose Gregorio Hernandez Cisneros, a layman who died in 1919 whom the late Pope Francis called a "doctor close to the weakest."

Also from Venezuela is Maria Carmen Elena Rendiles Martinez, a nun born without a left arm who overcame her disability to found the Congregation of the Servants of Jesus before her death in 1977. She becomes the South American country's first female saint.

The Italian nuns to be canonized are Vincenza Maria Poloni, the 19th century founder of Verona's Institute of the Sisters of Mercy, which cares primarily for the sick in hospitals, and Maria Troncatti of the Daughters of Mary Help of Christians.

In the 1920s, Troncatti arrived in Ecuador to devote her life to helping Ecuador's indigenous population.