[FLASH] White House tells OpenAI and Anthropic to withhold new frontier models from the UK AI Security Institute pending US review
Politico reported Thursday that the Office of the National Cyber Director asked both labs not to give frontier models to the UK AI Security Institute before US review ('this has been our policy with every new frontier model'); Bloomberg confirmed Friday with a British official. Anthropic's Mythos 5.1 went 'only to a set of U.S. organizations'; AISI says it tested GPT-6 Astra pre-release; the UK says 'no country can tackle them alone'. OpenAI declined comment. Next: any UK-US statement during UNGA week.