OpenAI CEO Sam Altman told employees last month that Google’s recent advances in artificial intelligence could create “temporary economic headwinds” for the company, according to an internal memo.

Altman said Google appears to have developed a new AI system whose training approach may surpass OpenAI’s own methods, prompting concerns inside the company’s research ranks. “We know there is still work that urgently needs to be done, and we are catching up quickly,” Altman wrote.

He also cautioned staff to brace for a more critical external environment. “I expect the sentiment around the company to be quite tough for some time,” he said.