White House asks OpenAI and Anthropic to hold new models from UK testers until US review, sources say.

President Donald Trump and OpenAI CEO Sam Altman during a lunch meeting at the G7 summit, in France, on June 17, 2026 Ludovic MARIN / AFP via Getty Images The White House seeks first access to new OpenAI and Anthropic models before the UK, sources told POLITICO. UK leaders are calling for a shared set of global principles. The request comes as the White House tries to determine how to handle powerful, new AI models The White House has asked OpenAI and Anthropic not to share their new artificial intelligence models with the UK government's testing agency until the models have gone through testing with the US government, POLITICO reported, citing a person familiar with the matter and a senior US administration official, both of whom were granted anonymity to describe the request. The request, which came from the Office of the National Cyber Director, puts companies in the difficult position of having to choose between withholding their models from UK's AI Security Institute — one of the most well-resourced government testing agencies in the world which previously enjoyed privileged early access to models — or risk upsetting the Trump White House. The senior administration official said the White House wants the US to review the models and take steps to make sure US systems are secure before the models are shared with US partners. "Because they're American companies and this has been our policy with every new frontier model that comes out," the senior official explained. The White House did not immediately respond to a request for comment. Anthropic appears to have agreed to the request, so far. The company did not provide its Claude Mythos 5.1 model to UK AISI, saying in its announcement that the model was "only available to a set of US organizations." "We're coordinating with the US government to expand access to a broader set of domestic and international partners as quickly as possible," an Anthropic blog announcing the model reads. Anthropic declined to comment for this piece. In a letter to a UK parliamentary committee earlier this month, AISI Director Henry de Zoete acknowledged the lack of access to Anthropic's model, but said: "We maintain strong relationships with all frontier AI developers and continue to have prerelease access to some of the world's most capable models," pointing out that it tested OpenAI's GPT-6 Astra model ahead of release. "The trusted relationships AISI holds enable us to test a range of models that represent industry-wide capability jumps," de Zoete wrote. OpenAI did not immediately respond to a request for comment. The Trump administration's request comes as the White House tries to determine how the government should handle powerful, new AI models that have hacked into outside entities during testing - including, as revealed yesterday, an Australian government website. It also comes as former engineers and leading officials from major AI companies warn of possible catastrophe if their models are left to advance unchecked. Created in 2023, the UK's AISI has established close links with leading AI labs, routinely testing their latest models ahead of public release on a voluntary basis. The UK government has made AISI's expertise and model access a central part of its domestic response to AI safety concerns, as well as its pitch to lead work on a global agreement on AI. Prime Minister Andy Burnham this week said AI will be "at the heart" of the country's G20 presidency next year. But AISI's privileged access to frontier models from leading American labs is under pressure from the Trump administration's insistence that the US government get first access to emerging systems. The UK has sought to downplay any clash, with Burnham saying at the UN General Assembly this week that the UK's institute was "working hand in glove with the US and the leading labs on AI safety." He called for a "single set of global principles and standards" to improve transparency and preparedness and ensure AI is developed safely. UK Foreign Secretary Ed Miliband made a similar case at the UN Security Council on Wednesday, saying governments need to ensure frontier models are "rigorously tested" and have enough visibility to assess what companies are doing. "The leading AI companies have actually committed to provide this visibility. It's really, really important, and it is an offer that we and they should follow through," Miliband said. "The UK is a world leader in AI security, and the AI Security Institute continues to work closely with the US government, international partners and leading AI companies, including OpenAI and Anthropic," a UK government spokesperson said. "These risks do not stop at national borders and no country can tackle them alone. We will continue to work closely with the US and other partners on the testing of advanced AI, while building our own rigorous scientific understanding of these systems and ensuring our approach is grounded in the evidence." In the US, Congress and the W