US Government Bans Foreign Access to Anthropic’s Claude Fable 5 and Mythos 5 Models

Anthropic’s newest large‑language models, Claude Fable 5 and Mythos 5, have become the focus of a severe export‑control action by the U.S. government. According to a report by Axios, the Trump administration, invoking national‑security authority, issued a letter from Commerce Secretary Howard Lutnick to Anthropic CEO Dario Amodei stating that both models are now subject to export restrictions covering any location outside the United States and all foreign persons within the United States.

The restriction is not merely a ban on overseas subscriptions; it places the models in the same regulatory framework as high‑end chips and sensitive software. A government official disclosed that the move was prompted by a separate company’s claim of successfully jail‑breaking Mythos, raising concerns about potential national‑security threats.

Prior to this letter, the U.S. government had attempted to persuade Anthropic to pause the release of the models but was unsuccessful. Reuters later reported that earlier in the month President Trump signed an executive order requiring leading AI developers to voluntarily submit their most powerful models for government cybersecurity testing before public release.

The Commerce Department indicated that, until the national‑security system is reinforced, the models must remain blocked, a process expected to take several weeks. Export, re‑export, or transfer of the models to foreign entities within the United States will require a specific license, and Anthropic must submit additional applications for item‑by‑item verification. Non‑compliance could result in civil and monetary penalties.

Anthropic has issued a statement acknowledging the restrictions. The situation is further complicated by the company’s recent inclusion on a Pentagon blacklist, which labels it as too dangerous for U.S. government use, while simultaneously subjecting it to Commerce Department licensing for foreign use.

Reference links: https://www.axios.com/2026/06/12/anthropic-trump-mythos-fable-national-security, https://www.reuters.com/technology/us-blocks-foreign-access-anthropics-most-advanced-ai-models-axios-reports-2026-06-13/, https://x.com/AnthropicAI/status/2065597531644743999