The White House has asked OpenAI and Anthropic to hold back new AI models from the U.K.'s AI Safety Institute (AISI) until U.S. agencies review them first, Politico reports. The request came from the Office of the National Cyber Director, forcing both companies to choose between withholding models from AISI and angering the White House. Anthropic has already fallen in line, making Claude Mythos 5.1 available only to U.S. organizations.

AISI is one of the best-equipped government AI testing agencies in the world, with early access to frontier models from top labs. It recently became the first to report autonomous deception by AI agents in real-world settings. In a letter to Parliament, AISI Director Henry de Zoete said the agency still has access to frontier models and tested OpenAI's GPT-6 Astra before release.

Prime Minister Andy Burnham played down the conflict at the UN General Assembly, calling for "shared global principles and standards." The responsible U.S. agency, the Center for AI Standards and Innovation (CAISI), has its own problems. It has no permanent director and only a few dozen staffers.

Politico

AISI letter to British Parliament