Donald Trump has threatened to impose “a big tariff” on the UK if it does not drop its digital services tax on US social media firms.

The digital services tax, introduced in 2020, imposes a 2% levy on the revenues of several big US tech companies.

Speaking to reporters from the Oval Office on Thursday, the US president said: “We’ve been looking at it and we can meet that very easily by just putting a big tariff on the UK, so they better be careful.

“If they don’t drop the tax, we’ll probably put a big tariff on the UK.”

The tax targets companies whose worldwide revenues from digital activities exceed £500m ($673m), with more than £25m of the revenues from UK users.

While it raises more than most of the targeted businesses pay in UK corporation tax, Amazon, Google and Apple pass the tax on to the bills of the third-party businesses and sellers that use their sites.

The Trump administration is vowing to crack down on foreign tech companies’ exploitation of US artificial intelligence models, singling out China at a time that country is narrowing the gap with the US in the AI race.

In a Thursday memo, Michael Kratsios, the president’s chief science and technology adviser, accused foreign entities “principally based in China” of engaging in deliberate, industrial-scale campaigns to “distill,” or extract capabilities from, leading AI systems made in the US and “exploiting American expertise and innovation.”

The administration, Kratsios wrote, will work with American AI companies to identify such activities, build defenses and find ways to punish offenders.

The memo arrives at a time when China is challenging US dominance in artificial intelligence, an area where the White House says the US must prevail to set global standards and reap economic and military benefits. But the US-China gap in performance of top AI models has “effectively closed,” according to a recent report from Stanford University’s Institute for Human-Centered AI.

China’s embassy in Washington said it opposed “the unjustified suppression of Chinese companies by the US”.

An internal Pentagon email outlines options for the United States to punish Nato allies it believes failed to support US operations in the war with Iran, including suspending Spain from the alliance and reviewing the US position on Britain’s claim to the Falkland Islands, a US official told Reuters.

The policy options are detailed in a note expressing frustration at some allies’ perceived reluctance or refusal to grant the United States access, basing and overflight rights - known as ABO - for the Iran war, said the official, who spoke on condition of anonymity to describe the email.

The email stated that ABO is “just the absolute baseline for Nato,” according to the official, who added that the options were circulating at high levels in the Pentagon.

One option in the email envisions suspending “difficult” countries from important or prestigious positions at Nato, the official said.

A majority of Americans blame Donald Trump for surging gasoline prices, which is weighing on his Republican party ahead of November’s congressional midterm elections, according to a Reuters/Ipsos poll.

Some 77% of registered voters in the poll, which concluded early this week, said Trump bears at least a fair amount of responsibility for the recent rise in gas prices, which was sparked by his decision to launch a war on Iran along with US ally Israel.

The view was widely shared across the political spectrum, with 55% of Republican voters, 82% of independents and 95% of Democrats pinning blame on the president for the higher costs.

Some 58% of voters, including one in five Republicans and two-thirds of independents, said they would be less likely to support candidates in the November midterms who support Trump’s approach to the conflict with Iran.