Boris Johnson has put himself at odds with Donald Trump by vowing to tax US internet giants like Google more – despite Washington threatening France with a “trade war” over similar measures.

The prime minister stressed that he “deplores” trade wars and vowed to press ahead with his manifesto commitment to a digital services tax, insisting online companies “need to make a fairer contribution”.

Trump’s administration has threatened to impose 100% tariffs on up to $2.4bn (£1.85bn) worth of French goods, including Champagne, arguing that Paris’s proposed digital services tax discriminates against tech giants.

The US has also warned Italy, Austria and Turkey, which have all introduced similar digital services taxes, that they could face action, according to the Financial Times.

But on the election campaign trail in Salisbury, Johnson said: “Obviously I deplore – I don’t think trade wars are a good thing. 

“One of the things the UK is going to do is campaign for – when we take back control of our tariffs, which we will on January 31, I hope, I know – we will campaign for freer trade and make sure we will open up markets around the world for British goods and services. 

“That’s one of the objectives of our government. 

“On the digital services tax, I do think we need to look at the operation of the big digital companies and the huge revenues they have in this country and the amount of tax that they pay. 

“We need to sort that out. 

“They need to make a fairer contribution.” 

It comes as the prime minister and Trump prepare to hold separate press conferences at the Nato summit in Watford on Wednesday.

Johnson has unusually decided not to have a bilateral meeting with Trump, amid fears that the unpopular president could derail his general election campaign.

The president on Tuesday vowed to “stay out” of the election because he does not want to “complicate it”.

But his press conference could still be risky for Johnson given Trump’s tendency to go off script and Jeremy Corbyn’s attempts to goad him into an outburst.

Johnson’s criticism of Trump’s protectionism, which has also included a trade war with China, could add to the sense of danger for the Tories.

Terror law

Meanwhile, Johnson announced plans to ensure big public venues are compelled by law to ramp up security in the face of the terror threat.

The family of Martyn Hett, a victim of the 2017 Manchester attack, has been campaigning to ensure major venues assess the threat of a terrorist attack and take steps to prepare as part of their health and safety strategy.

Announcing plans to introduce “Martyn’s law” either under new or existing legislation, the PM said: “The nature of threats faced by British citizens has changed in the evolution of modern extremism.

“It is no longer sufficient for public venues to prepare for accidental threats like fire. They need to reduce their vulnerability to people who seek to perpetrate violent acts too.

“We must not let the terrorists alter our way of life. In our open and tolerant society, the freedom for citizens to enjoy markets, concerts, gigs and restaurants must continue as before. 

“But there are steps we can and will take to make public spaces as secure as possible.”

Figen Murray, Martyn Hett’s mother, said: “When Martyn died I promised both myself and him that I would do everything in my power to stop other families going through what we were.

“Today is a real breakthrough in those efforts and I thank the Prime Minister for responding in the way he has. Martyn’s law won’t stop terrorism – nothing can – but it will make it harder to commit. It’s the sort of common sense law that most people would think already existed. Thank you to everyone who has supported the campaign and to all of my fellow survivors at Survivors Against Terror for your help in making it happen.”

Charlotte Dixon-Sutcliffe, whose partner David was killed in the Brussels metro bombing, and is chair of Survivors Against Terror, said: “We strongly welcome the commitment of the prime minister to support Martyn’s Law and the survivor’s charter.

“Combined these two policies will make our country safer and provide the sort of support to survivors that the British public would expect. We also welcome today’s commitment from the Labour Party to support the charter.”