U.S. authorities have ordered Anthropic to block foreign users from accessing its most advanced artificial intelligence models. According to the TASS news agency, the measure affects the Fable 5 and Mythos 5 models, which were to be immediately cut off from all users outside a defined group, according to a decision by the U.S. government.

Anthropic stated that it was forced to disable access to these models for all customers. The company cited export control guidelines issued by the U.S. government, citing national security concerns, as the reason.

"The U.S. government, citing authorities in the area of national security, has issued an export control directive that requires the suspension of all access to the Fable 5 and Mythos 5 models for all foreign nationals, whether they are located in the United States or abroad, including foreign employees of Anthropic. The practical consequence of this regulation is that we must abruptly shut down Fable 5 and Mythos 5 for all of our customers in order to ensure compliance with the regulations," the company said in a statement.

Anthropic added that it received the directive on Friday evening. According to the company, the letter did not contain specific details about the security risk. The government only verbally informed them of a method that had been discovered to bypass the security safeguards of the models. The company emphasized that it complied with the regulation, even though it believes that the discovery of a "narrowly defined potential jailbreak" does not justify the removal of a commercial model used by hundreds of millions of people.

"If this standard were applied across the industry, we believe it would effectively halt the deployment of all new models," Anthropic warned.

Anthropic was founded in 2021 by former employees of OpenAI. In a short period of time, it has become one of the leading developers of artificial intelligence systems. The company has long positioned itself as a creator of "ethical AI" and emphasizes the safe implementation of neural technologies. It launched its first chatbot, Claude, in March 2023.

According to TASS, tensions between U.S. authorities and the company escalated in March 2026, when the U.S. Department of War identified Anthropic as a threat in the supply chain, effectively severing business ties with the company. The dispute arose from the Pentagon's request to use Anthropic products "for all lawful purposes." The company's management rejected this, with the exception of two cases: the technology should not be used for domestic mass surveillance or for the development of lethal autonomous weapon systems.

gnews.cz - GH