NEW YORK (AP) -- X CEO Linda Yaccarino said she's stepping down after two years running Elon Musk's social media platform.

Yaccarino posted a positive message Wednesday about her tenure at the company formerly known as Twitter and said "the best is yet to come as X enters a new chapter with" Musk's artificial intelligence company xAI, maker of the chatbot Grok.

Musk hired Yaccarino, a veteran ad executive, in May 2023 after buying Twitter for $44 billion in late 2022.

He said at the time that Yaccarino's role would be focused mainly on running the company's business operations, leaving him to focus on product design and new technology.

In accepting the job, Yaccarino was taking on the challenge of getting big brands back to advertising on the social media platform after months of upheaval following Musk's takeover.

A number of companies had pulled back on ad spending -- the platform's chief source of revenue -- over concerns that Musk's thinning of content restrictions was enabling hateful and toxic speech to flourish.

Two years later, those concerns have not subsided. A recent update to Grok led to a flood of antisemitic commentary from the chatbot this week that included praise of Adolf Hitler.

"We are aware of recent posts made by Grok and are actively working to remove the inappropriate posts," the Grok account posted on X early Wednesday, without being more specific.