(OSV News) — Vice President JD Vance said he wanted to “endorse” Pope Leo XIV’s concerns about artificial intelligence and warfare during remarks May 28 at the U.S. Air Force Academy commencement ceremony in Colorado Springs.

Vance, the second Catholic to hold the office of vice president and a proponent of AI technology, acknowledged that some tech industry executives had been booed by other 2026 graduating classes and that people are “understandably worried” about the implications of the emerging technology.

Pointing to Pope Leo’s new encyclical, “Magnifica Humanitas: On Safeguarding the Human Person in the Time of Artificial Intelligence,” in which the pontiff called for “the most rigorous ethical constraints” on the use of AI in warfare, Vance said, “I want to endorse that sentiment and make it more specific to each and every one of you.”

The graduates, Vance said, will face the “incredible burden” of warfare as members of the U.S. armed forces, and they must ensure that warfare is conducted justly.

“If the warfare of the future is to live up to the moral values of our ancestors, decisions over life and death must be made by humans and not machines,” Vance said. “So as AI transforms the battlefield — in some ways positively, in some ways not — I ask that you be jealous and selfish about your role as a decision-maker in warfare. Use technology to make you better, but never submit to it. You are the masters of warfare, and both your minds, but also your hearts are the opposite of artificial.”

In the encyclical, Pope Leo wrote that “moral judgment cannot be reduced to calculation,” and so “it is not permissible to entrust lethal or otherwise irreversible decisions to artificial systems.”

While AI must reflect alignment with human moral values, Pope Leo dismissed the concept of “artificial moral agents” that would seek to replace a human being’s moral judgement, which involves “conscience, personal responsibility and the recognition of the other as a person.”

In the document, Pope Leo addressed the just war theory, largely formulated by St. Augustine and St. Thomas Aquinas, which has been accepted for centuries by the Church to determine whether warfare could be morally justified under certain strict conditions. He argued the theory has become increasingly insufficient in modern circumstances, in part due to the rise of AI, and “is now outdated.”

“The Holy See has recently observed that the growing ease with which autonomous weapons systems can be deployed makes war more ‘feasible’ and less subject to human control,” Pope Leo wrote. “This violates the principle that armed force should be used only as a last resort in cases of legitimate self-defense.”

The U.S. president or the vice president traditionally speaks at the commencement ceremonies for one of the military service academies every year.

Vance previously told NBC News in an interview published May 26 that he had not yet finished reading the document in its entirety, but had read “bits and pieces” of the encyclical and some coverage of the document.

“What I read of it sounds very profound,” Vance said at that time.