Speaking in a late slot on Tuesday to a sparsely populated hall, Mr Johnson discussed the potential perils of new technological advances while hailing London as having "the biggest tech [industry] anywhere in Europe".
The speech came on a day when the Supreme Court ruled that his decision to prorogue Parliament was unlawful, making the address his last commitment before cutting his trip to New York short and returning early to the UK.
The prime minister littered his speech with jokes about futuristic "hangover cures", the threat of "pink-eyed Terminators", "terrifying limbless chickens" and household devices that "monitor your nightmares, monitor your fridge".
But he did manage to squeeze in one dig at his own country's MPs, accusing them of wanting the Brexit process to go on forever.
He made the comment during a discussion of the classical myth of Prometheus, a Titan condemned by Zeus to eternal torture.
"It is a trope as old as literature that any scientific advance is punished by the gods," he said. "When Prometheus brought fire to mankind in a tube of fennel… Zeus punished him by chaining him to a Tartarian crag while his liver was pecked out by an eagle.
"And this went on forever. A bit like the experience of Brexit in the UK, if some of our Parliamentarians had their way."
The joke, as well as this and other classical references during Mr Johnson's speech, drew a few laughs but largely appeared to fall flat in the nearly deserted hall. The Press Association reported that London's UN ambassador Karen Pierce, at least, laughed along.
On AI, Mr Johnson said: "Above all, we need to agree a common set of global principles to shape the norms and standards that will guide the development of emerging technology."
He also extended an invitation to those gathered in the room.
"So - here's the good news - I invite you next year to a summit in London," he said, before praising the city for having "perhaps half a million people working in tech alone".
"I hope you will come there, where we will seek to assemble the broadest possible coalition to take forward this vital task."
It was not clear if Mr Johnson was referring to London Tech Week, which began in 2014 and takes place each June, or a new event. Neither Downing Street nor the Department for Digital, Culture, Media & Sport were able to provide clarification.
Additional reporting by agencies
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