United Kingdom, June 16 -- Cyber security experts have urged the White House to reverse restrictions placed on some of Anthropic's most advanced AI systems, arguing the measures could undermine efforts to protect critical digital infrastructure.

Researchers and executives from major technology firms, including Adobe, Nvidia and Zoom, signed an open letter addressed to US Secretary of Commerce Howard Lutnick and National Cyber Director Sean Cairncross.

The group described the recent restrictions as "dangerous".

Anthropic, the company behind the Claude chatbot, was ordered last week to suspend access to its Fable 5 and Mythos 5 models for foreign nationals.

To comply with the directive, the company blocked access to the models across it...