In the audience were a mix of British officials and business executives, including Demis Hassabis, the chief executive of Google’s A.I. lab DeepMind. The musical artist Will.i.am sat in the front row.

Some saw Mr. Sunak’s conversation with Mr. Musk as a not-so-subtle attempt to raise Britain’s standing with entrepreneurs and tech companies at a time when the country’s economy is languishing. At a news conference earlier on Thursday, a British journalist asked Mr. Sunak if the meeting was about A.I. or trying to lure a Tesla battery plant to Britain. (Mr. Sunak praised Mr. Musk’s expertise about A.I.)

“He wants the U.K. to attract investments,” said Marietje Schaake, the international policy director at Stanford’s Cyber Policy Center, who moderated one of the discussions at the A.I. Safety Summit. The Musk interview, she said, “looks a bit like a media stunt.”

Mr. Sunak’s conversation with Mr. Musk veered, at times, toward science fiction. Mr. Musk outlined a future in which computers would surpass human intelligence and people would not have to work. At another point, he discussed the creation of humanoid robots that would need off switches.

In an unexpected heartfelt moment, Mr. Musk said A.I. systems could become so advanced that it could be a person’s “great friend” by remembering conversations and learning their likes and dislikes. He noted that his son has learning disabilities and trouble making friends. “An A.I. friend would be great for him,” he said.