Meta said it will introduce more guardrails to its artificial intelligence (AI) chatbots - including blocking them from talking to teens about suicide, self-harm and eating disorders.

It comes two weeks after a US senator launched an investigation into the tech giant after notes in a leaked internal document suggested its AI products could have "sensual" chats with teenagers.

The company described the notes in the document, obtained by Reuters, as erroneous and inconsistent with its policies which prohibit any content sexualising children.

But it now says it will make its chatbots direct teens to expert resources rather than engage with them on sensitive topics such as suicide.

"We built protections for teens into our AI products from the start, including designing them to respond safely to prompts about self-harm, suicide, and disordered eating," a Meta spokesperson said.