The U.S. government instructed Anthropic on Friday evening to prevent any foreign national from accessing its latest models, the company said.
Anthropic said it had to disable access to Fable 5 and Mythos 5 for all customers — not just foreign nationals — to comply with the directive.
The company wrote, "The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance."
"The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees," the company wrote in a statement posted online late Friday evening.
Claude’s landing page said that "Fable 5 is temporarily unavailable" as of Friday evening, and Anthropic is the company behind the popular Claude chatbot.
The letter issuing the directive was sent from Commerce Secretary Howard Lutnick and was written with the help of officials from the Commerce Department’s Bureau of Industry and Security, an administration official said. The Commerce Department did not immediately reply to a request for comment.
Anthropic said the government had identified a specific technique that could allow users to circumvent some narrow safeguards and that the government had provided only "verbal evidence" of the issue; the company said the workaround was likely present in other AI systems. "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," Anthropic wrote and said it believed the directive stemmed from "a misunderstanding" and hoped to reinstate access as soon as possible.
Anthropic released Fable 5 and Mythos 5 on Tuesday, calling them the most powerful AI systems it had ever shared. Only Fable 5 was released to the general public with stronger restrictions on certain topics, while Mythos 5 was released without such safeguards to a select group of trusted partners, including key cybersecurity and infrastructure companies.
In February, President Donald Trump and Defense Secretary Pete Hegseth moved to bar Anthropic’s products from federal agencies after the company sought stronger guardrails on Pentagon use; Trump posted on Truth Social that "The Leftwing nut jobs at Anthropic have made a DISASTROUS MISTAKE trying to STRONG-ARM the Department of War." Anthropic later sued the administration arguing the administration's violated Anthropic’s freedom of speech, a federal judge in California ruled in Anthropic’s favor, and the case remains active in a Washington, D.C. federal court. The Financial Times reported last week that the National Security Agency was using Mythos to conduct offensive cyberattacks, and on June 2 Trump signed an executive order on AI directing federal agencies to bolster cyber defenses and to design a mechanism for early access to the most powerful AI models.