The prime minister will host an event with X owner Elon Musk following the UK's AI summit.
Rishi Sunak's X account posted on Monday that he will be "in conversation" with the Tesla and SpaceX boss on Thursday.
It is likely he will also be present in some way at the summit, although it is not clear whether he will attend in person or virtually.
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Reports emerged on Monday that the value of X had fallen to $19bn (£15.6bn) according to the company's internal documents. Musk bought the site - then called Twitter - for $44bn (£36.2bn) last year.
US vice president Kamala Harris will also attend the summit.
While in the UK, she will discuss the Israel-Hamas conflict with Rishi Sunak during a whirlwind visit.
The pair will also "consult on next steps in our support for Ukraine," according to a White House official.
Ms Harris's presence at the AI summit means that President Joe Biden is not making the trip.
Downing Street has denied Mr Sunak is feeling snubbed by international counterparts, with Canadian Prime Minister Justin Trudeau, French President Emmanuel Macron and German Chancellor Olaf Scholz all believed to be unlikely to show.
An updated guest list could not be provided by the UK government on Monday, although a spokesperson claimed they "remain confident that we have brought together the right group of world experts in the AI space, leading businesses, and indeed world leaders and representatives who will be able to take on this vital issue".
This came amid reports the invite to China has been upgraded to include asking President Xi Jinping to attend.
Downing Street insist it is a "significant achievement" to host the first AI safety summit of its kind.
After arriving in the UK on Tuesday, Ms Harris and her husband will travel to Winfield House in London.
She will give a "major policy speech" on the US's vision for AI on Wednesday at the US embassy, before heading to Downing Street to meet with Mr Sunak.
Ms Harris will travel to Milton Keynes on Thursday to attend the AI summit, which will take place at Bletchley Park - where British codebreakers worked in secret, using early computer technology, during the Second World War.
The vice president will then leave the UK later that day to return to the US.
Mr Biden signed an executive order earlier today aiming to guide the development of AI, requiring firms working on potentially dangerous models to share safety data with the government before their release, among other measures.