Amazon CEO Andy Jassy was among the tech leaders who raised concerns to senior Trump administration officials this week about security risks in Anthropic’s most advanced models, according to two people familiar with the conversations.

The calls between the head of Amazon—one of Anthropic’s biggest investors and vendors—and the officials in the last few days helped set in motion the Trump administration’s new export restrictions on Anthropic’s Claude Mythos 5 and Fable 5 models late Friday night, citing national security concerns, the people said. Those restrictions suspend access to those models to foreign nationals. Anthropic said it disabled access to the models for all customers to comply.