Anthropic announced it has received partial relief from US restrictions placed on its newest AI models.

In a statement, the company noted that the government approved limited access to Mythos 5 last Friday. Access to Fable 5 continues to be restricted.

"Since June 12, we have been collaborating closely with the US government to restore access to Claude Mythos 5 and Fable 5. Today, the government informed us that Mythos 5, our most advanced cybersecurity model, can be made available again to certain US organizations that operate and defend critical infrastructure," Anthropic stated.

"We are quickly restoring access for these organizations and will keep working with the government to broaden access to Mythos 5 and restore Fable 5 for general availability."

This partial reversal follows Anthropic's decision two weeks ago to disable access to both Fable 5 and Mythos 5 due to a US export-control order. The order prohibited access by foreign nationals, including those employed at Anthropic's San Francisco headquarters.

At the time, Anthropic linked the order to government worries about bypassing model safeguards. The company challenged the seriousness of the concerns and noted that the government failed to share specific details regarding its national security issues.

The move represents one of the most direct interventions by the US government in the release of a frontier AI model, prompting questions about the administration's approach to regulating powerful models with potential national security implications.

Anthropic's main competitor, OpenAI, revealed on Friday that the US government asked it to restrict preview access to its latest models, GPT-5.6, to a small group of trusted partners.

OpenAI stated in response that such government-mandated limits should not become standard practice.

"We do not think this type of government access process should turn into the long-term standard," the company said. "It prevents the best tools from reaching users, developers, enterprises, cyber defenders, and global partners who require them."