OpenAI and Anthropic both restrict access to their newest, highest-capability AI models as the US government reviews national security and cybersecurity risks. OpenAI says it delays broad availability of its GPT-5.6 Sol model at the request of President Donald Trump’s administration, offering it only to a small set of “trusted” customers approved by the government while safeguards and testing continue. OpenAI says the phased approach is temporary and aims to support wider release in coming weeks.

Anthropic initially pulls its cybersecurity-focused Claude Mythos 5 and the more widely available “Fable 5” after a June export-control directive tied to concerns about alleged ways to bypass safeguards. Reporting describes the government’s action as preventing use by foreign nationals, with Anthropic saying it disabled access globally because it could not reliably filter by citizenship. The company later says the US government partially restores access to Mythos 5 for a set of US organizations that defend critical infrastructure, with more expansion planned; it also says it is working to restore general access for Fable 5.

The episode follows a broader Trump administration push for review of advanced “frontier” AI models and draws criticism about transparency and government control over who can access leading models, alongside support from others who argue additional testing is needed to reduce misuse risks.