Mr Hegseth was referring to an earlier row with Anthropic about the extent to which its AI could be used by the armed forces, a dispute that led the US department of war to designate the company a supply chain risk.
There are hopes that the current situation will be resolved in the coming days, potentially leading to the order being lifted. Anthropic has flown out some of its senior technical staff to Washington to meet with White House officials in a bid to ease tensions and address the Trump administration’s concerns, according to Axios.
However, the use of export controls has raised concerns that Britain could be dependent on the whims of the White House to secure access to advanced AI.
While the Government’s AI Security Institute is seen as world-leading in safety testing, Britain does not have any AI giants of its own, control any part of the industry, or have sufficient infrastructure to train its own systems.
Kanishka Narayan, AI minister, wrote on X on Saturday: “As we debate the future of national security and technological sovereignty, access to AI capabilities is crucial.”
In an effort to kickstart the AI industry in Britain, Sir Keir last week announced that the Government would spend £400m on AI chips from British companies. The Government also plans to invest £500m in start-ups through a Sovereign AI fund.
However, there are doubts about how effective these efforts will prove to be, given the sums involved. Nvidia, whose chips are widely used to train and run AI systems, is worth almost $5tn (£3.7bn) and its main customers, including Amazon, Google and Microsoft, spend hundreds of billions of dollars between them on its chips.
The White House has previously delayed access to advanced AI outside the US. Until this month, non-American companies were forbidden from joining Project Glasswing, Anthropic’s cybersecurity project that gave businesses access to an earlier AI model.
The Trump administration, which had adopted a laissez-faire attitude towards AI, has become increasingly interventionist in recent weeks amid growing concerns about the capabilities of the latest systems.
A Government spokesman said: “We are aware of reports that access to Anthropic’s Fable 5 and Mythos 5 models has been paused worldwide, including in the US, following an export control directive from the US Government.
“We are in contact with both the US Government and Anthropic to understand the full picture and are monitoring the situation closely.”