Pope Leo XIV has sounded the alarm over the use of artificial intelligence (AI) in the military, saying delegating such decisions to machines was a “destructive betrayal” of the principles that uphold civilization.

“Further technological advances and the military implementation of artificial intelligence have worsened the tragedy of armed conflict,” he said in his first message for World Peace Day, published Thursday.

“There is even a growing tendency among political and military leaders to shirk responsibility, as decisions about life and death are increasingly ‘delegated’ to machines,” he said.

“This marks an unprecedented and destructive betrayal of the legal and philosophical principles of humanism that underlie and safeguard every civilization,” he added.

The Catholic Church’s first US pope, who was elected in May, has repeatedly called for AI to be used in an ethical fashion since his election in May.

Several countries have begun to use AI to automate surveillance, cyber defence and weapons systems — such as autonomous drones or anti-missile systems equipped with predictive algorithms, raising serious ethical dilemmas.

In the message, published ahead of World Peace Day, which is celebrated by the Church on 1 January, Leo also denounced the use of religion for political ends.

“Unfortunately, it has become increasingly common to drag the language of faith into political battles, to bless nationalism, and to justify violence and armed struggle in the name of religion,” he said.

The 70-year-old also said the idea of military might — and nuclear deterrence in particular — “is based on the irrationality of relations between nations,” built “not on law, justice and trust but on fear and domination by force.”