Elon Musk’s artificial intelligence startup xAI is burning through $1 billion a month as the cost of building its advanced AI models races ahead of the limited revenues, according to people briefed on the company’s financials.

Elon Musk has promised that his AI business, xAI, will help to revolutionize society. Before it can do that, however, the company is going to need to become fiscally viable—a goal it hasn’t quite met yet.

The European Union said on Thursday it was seeking more information from Elon Musk's X about changes to its corporate structure, months after the social media platform was bought by xAI in a $33 billion deal.