Pope Francis called on Friday for a ban on "lethal autonomous weapons", when he addressed the G7 leaders' summit in Italy on the perils of artificial intelligence.

"In light of the tragedy that is armed conflict, it is urgent to reconsider the development and use of devices like the so-called 'lethal autonomous weapons' and ultimately ban their use," the pope said.

"This starts from an effective and concrete commitment to introduce ever greater and proper human control. No machine should ever choose to take the life of a human being," he said.

Francis, the first head of the Catholic Church to ever attend a Group of Seven summit, has repeatedly denounced the arms industry and those he says profit from wars and death.

AI is already being used on the battlefield and its move into modern warfare is raising concerns about the risks of escalation and the role of humans in decision making.

AI has shown itself to be faster but not necessarily safer or more ethical, and the development of weapons systems that could kill without human intervention poses ethical and legal challenges.

Francis told the leaders gathered in the southern Italian region of Puglia: "Artificial intelligence (is) at the same time an exciting and fearsome tool."

"We would condemn humanity to a future without hope if we took away people's ability to make decisions about themselves and their lives, by dooming them to depend on the choices of machines," he warned.

The G7, which brings together Britain, Canada, France, Germany, Italy, Japan and the United States, said on Friday that AI "can play a crucial role in promoting progress and development in our societies".

"We recognise the impact of AI on the military domain and the need for a framework for responsible development and use," the leaders said in a draft statement seen by AFP.

At a strategic level, AI will produce models of battlefields and propose how to respond to attacks, maybe even including the use of nuclear weapons.

"We need to ensure and safeguard a space for proper human control over the choices made by artificial intelligence programs: human dignity itself depends on it," Francis said.

The Argentine pontiff was speaking after a series of bilaterals, including with Ukraine's President Volodymr Zelensky, French President Emmanuel Macron and Canadian Prime Minister Justin Trudeau.