The newly elected Pope Leo XIV has urged the Catholic Church to urgently address a growing lack of faith in his inaugural mass at the Vatican.

Speaking just a day after his election as the 267th Pope and the first American to lead the Church, he cautioned that individuals were increasingly abandoning faith in favour of "technology, money, success, power, or pleasure."

In his first address as Pontiff, Pope Leo declared that he had been chosen to serve as a "faithful administrator" of a Church that would act as a "beacon that illuminates the dark nights of this world."

The ascension of Robert Francis Prevost to the papacy has been met with widespread celebration among the world's 1.4 billion Catholics, with particularly jubilant scenes in his native United States and in Peru, where he dedicated two decades of his service.

Delivering his sermon today (9), the new Pope highlighted numerous contexts where Christian faith is often viewed as "absurd," with influence, affluence, and technological advancement holding sway.

However, he emphasized that it is precisely within these environments that missionary outreach is most critical.

"A lack of faith is often tragically accompanied by the loss of meaning in life, the neglect of mercy, appalling violations of human dignity, the crisis of the family and so many other wounds that afflict our society," he stated in his address, delivered in Italian.

Pope Leo XIV, aged 69, was clad in a white papal robe adorned with gold trim as he addressed the assembled cardinals within the Sistine Chapel.

The significant event was broadcast live by the Vatican administration, allowing Catholics worldwide to witness his first papal mass.

In an unscripted moment before his prepared homily, Pope Leo also appealed for unity within the Church from his fellow cardinals.

Speaking in his American-accented English, he said, "I know I can rely on each and every one of you to walk with me," underscoring his desire for a collaborative leadership within the Catholic Church.