Anthropic Blocks AI Models for Foreign Nationals After US National Security Order

Anthropic said Friday it has cut access to two powerful artificial intelligence (AI) models after a United States government order citing national security concerns.

The sudden block marks a major escalation in Anthropic’s growing showdown with the Trump administration after failed negotiations earlier this year over potential US military and intelligence use of its technology.

The order is potentially a major setback for Anthropic's plans to take the company public later this year.

What did Anthropic say about the block?

The San Francisco-headquartered firm said in a statement that it received a directive to block its Claude Fable 5 and Claude Mythos 5 for all foreign nationals.

Fable 5 and Mythos 5 are the newest versions of the Claude AI model, released on June 9. The first is widely available to the public, while the latter is mostly restricted to vetted organizations.

The company said the ban applied to foreigners "whether inside or outside the United States, including foreign national Anthropic employees."

However, Anthropic said it had blocked access for all customers for now to ensure compliance.

"Our understanding is that the [US] government believes it has become aware of a method of bypassing, or 'jailbreaking' Fable," the statement continued.

It said the company's own tests found only a small number of already-known bugs that were "minor vulnerabilities."

Anthropic said it was complying with the directive, but disagreed that the US government's findings "should be cause for recalling a commercial model deployed to hundreds of millions of people."

It added that if this rule were applied across AI platforms, "we believe it would essentially halt all new model deployments for all frontier model providers."

Why are the US government, Anthropic at loggerheads?

Anthropic’s relationship with the US government broke down this year after the company refused to allow the military to use its AI models for domestic surveillance and fully autonomous weapons systems.

In response, the Pentagon added Anthropic to a supply chain blacklist, which is set to take effect later this year and could severely limit the company’s federal contracts.

This latest export ban marks the second major action by the Trump administration against the AI firm in just a few months.

The New York Times described the order as "unusually expansive," noting it could prevent Anthropic's employees in allied nations, including Canada or the United Kingdom, from using the AI models.

Earlier this month, US President Donald Trump signed an executive order requiring federal vetting of the most advanced AI systems for national security risks for up to a month before public release.

Until this point, US export controls have mainly targeted AI chips and hardware, rather than limiting foreign access to the AI models themselves.

The block could also potentially hurt Anthropic's plans for a public listing or IPO as early as fall 2026 at a valuation approaching $1 trillion.

The ban raises fresh questions among investors about regulatory risks and the company’s ability to maintain its technological edge.