(Reuters) -The Motion Picture Association has sent a cease-and-desist letter to Meta, objecting to the social media platform's use of filters inspired by the PG-13 movie rating system for content moderation on Instagram for users under 18.

The trade group said Meta's claim that its filters align with the PG-13 rating is "literally false and highly misleading," because the Facebook parent's automated systems do not follow the curated, consensus-based process used for the film rating system.

Last month, Meta said its Instagram platform will limit what users under 18 can see on the platform using filters inspired by the PG-13 movie rating system.

The letter to Jennifer Newstead, Meta's chief legal officer, on October 28 asked Meta to immediately disassociate Teen Accounts and AI tools from the rating system and to refrain from any use of the PG-13 mark, seeking a resolution by November 3.

The MPA said PG-13 is a registered certification mark and that unauthorized use by Meta could erode public trust in its rating system, according to the letter reviewed by Reuters on Wednesday.

A Meta spokesperson said the company hopes to work with the MPA and made the change to address parents' concerns. The company said it never claimed a partnership with the MPA or that its content had been officially rated by the association.

Meta has stepped up safety measures on its social media platforms and artificial intelligence avatars after facing criticism from advocacy groups and lawsuits alleging the company failed to protect young users from harmful content.

Last month, Meta said that it will let parents disable teens' private chats with AI characters.

U.S. regulators have increased scrutiny of AI companies over potential harm from chatbots. In August, Reuters reported that Meta's AI rules allowed provocative conversations with minors.