Anthropic has disabled its most advanced artificial intelligence models after receiving a US government order on 12 June requiring it to suspend access for foreign nationals, a move that broadens Washington’s efforts to restrict access to cutting-edge AI capabilities on national security grounds.

The AI company said it had been directed to block foreign nationals from using its recently launched Fable 5 and Mythos 5 models, but chose instead to withdraw the systems for all users to ensure compliance. Anthropic said the export control directive did not provide detailed evidence supporting the government's concerns and described the action as a misunderstanding it is seeking to resolve.

According to Anthropic, US officials believe a "jailbreak" technique could bypass safeguards designed to prevent Fable 5 from being used to identify software vulnerabilities. The company said it had reviewed the alleged technique and found it could uncover only a small number of previously known flaws that other publicly available AI models can already detect.

In a company statement, Anthropic said: "We disagree that the finding of a narrow potential jailbreak should be cause for recalling a commercial model deployed to hundreds of millions of people." The company added that applying the same standard across the industry would "essentially halt all new model deployments for all frontier model providers".

Reuters reported that a US official confirmed the Commerce Department had issued the directive covering all foreign nationals. The order represents a significant shift in US export controls, which have historically focused on restricting advanced semiconductors and AI infrastructure rather than direct access to AI models themselves.

The dispute comes against the backdrop of a deteriorating relationship between Anthropic and the Trump administration. Reuters reported that the company was placed on a Pentagon supply chain blacklist after refusing to allow its technology to be used for domestic surveillance and fully autonomous weapons systems, although signs of a thaw had recently emerged.

Kirsten Davies, the Pentagon's chief information officer, defended the government's position in a post on X, saying: "Some things are simply more important than revenue cycles, clickbait, and pre-IPO valuation. America First. Always."

European officials are examining the implications of the move. Thomas Regnier, a European Commission spokesperson, said the development was "a further illustration of why Europe needs to strengthen its technological sovereignty" as Brussels assesses the impact on users across the bloc.

The suspension comes only days after Anthropic publicly released Fable 5 and weeks after the company confidentially filed for a US initial public offering, placing it ahead of rival OpenAI in the race to reach public markets.

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