NEW YORK — In a profanity-laced outburst, Elon Musk has slammed advertisers that have left X, warning they will kill the social media platform.

At an event in New York, he accused companies that have joined an ad boycott of the site formerly known as Twitter of trying to blackmail him.

"Go [expletive] yourself," the billionaire said in an interview.

Some firms have paused advertising on X amid concerns over antisemitism, including a post from Musk himself.

The Tesla and SpaceX boss apologised on Wednesday for that post, saying it might be the "dumbest" thing he has ever shared online.

But it was his response to a question about an advertising boycott by companies including Disney, Apple and Comcast that caused a stir at the gathering of leaders from the worlds of business, politics and culture.

"I don't want them to advertise," Musk said at the New York Times' DealBook Summit.

"If someone is going to blackmail me with advertising or money go [expletive] yourself.

Go. [Expletive]. Yourself. Is that clear? Hey Bob, if you're in the audience, that's how I feel."

He was apparently referring to Disney chief executive Bob Iger, who spoke at the summit earlier in the day.

In the room with Musk was Linda Yaccarino, X's chief executive, who has been charged with trying to bring back advertisers to the platform.

Musk also said that advertisers could kill X.

"What this advertising boycott is going to do is it's going to kill the company," he said.

"The whole world will know those advertisers killed the company, and we will document it in great detail," he added.

Ms Yaccarino has since reposted what she called his "candid interview", adding her perspective on advertising that "X is standing at a unique and amazing intersection of Free Speech and Main Street — and the X community is powerful and is here to welcome you".

Musk has been on a visit to Israel after he last month appeared to personally back an antisemitic conspiracy theory.

"I'm sorry for that tweet... it might be literally the worst and dumbest post that I've ever done," he said on Wednesday.

The boycott isn't just to do with that post, though.

Many advertisers had already decided to spend their dollars elsewhere.

In an interview with the BBC in April, Musk said "almost all of them [advertisers] have either come back or they're going to come back".

Three months later he acknowledged in a post on X that ad revenue had fallen by 50%.

That was before a report by liberal pressure group Media Matters, which claimed to have found evidence that some adverts had been placed next to Nazi content.

X says the group's report had "misrepresented the real user experience of X" in order to "undermine freedom of speech and mislead advertisers". X has filed a lawsuit against Media Matters.

It's hard to see how Musk's comments will bring advertisers running back. The company is heavily reliant on their money.

It is unclear how much of X's revenue currently comes from ads, because it's now a private company and no longer publishes quarterly reports.

But before Musk took over the firm, advertising made up about 90% of Twitter revenue. — BBC