Amazon signed the Nvidia- and Microsoft-backed Open Weights and American AI Leadership letter, saying it supported the "macro direction" even though some elements "need further definition over time."

The endorsement came after Anthropic CEO Dario Amodei said the company had never advocated a ban on open-weight models. Instead, he called for keeping powerful chips out of authoritarian hands, stopping industrial-scale distillation and requiring safety testing of "all sufficiently capable models, open and closed," while disputing claims that open-weight models inherently make it easier to develop safeguards.