Donald Trump has said he is tearing up part of the tariff deal he struck with EU leaders at his golf course in Scotland last summer, criticising Brussels for taking so long to ratify the deal.

Blindsiding Brussels late on Friday, a public holiday in much of Europe, he announced that he would be increasing tariffs on cars and lorries imported into the US from the EU from 15% to 25% from next week.

Vehicles made in the US by EU companies would be exempt from the increase, he wrote on Truth Social.

“I am pleased to announce that, based on the fact the European Union is not complying with our full agreed to Trade Deal, next week I will be increasing Tariffs charged to the European Union for Cars and Trucks coming into the United States,” Trump wrote.

In a follow-up comment, he said – appearing to refer to EU promises of investments – that “many automobile and truck plants are currently under construction with 100 Billion Dollars being invested, A RECORD in the History of Car and Truck Manufacturing. These Plants, staffed with American Workers will be Opening Soon.”

The EU parliament’s international trade committee chair, the German MEP Bernd Lange, responded immediately, saying Trump’s announcement proved how untrustworthy the US now was.

“This is no way to treat close partners,” Lange said. “Now we can only respond with the utmost clarity and firmness, drawing on the strength of our position.”

Although the European parliament voted at the end of March to progress the deal, it still has not been formally signed off in what is known as the “trilogue” process, involving signatures from the European Commission, the European council of EU leaders and the parliament.

The EU is likely to launch an intense diplomatic campaign to bring the deal back from the brink.

The latest tariff development comes as Trump threatened to withdraw US troops from Italy and Spain, a day after saying he was looking at reducing the number deployed in Germany.

Asked late on Thursday if he would consider pulling US troops out of Italy and Spain, he told reporters: “Probably … look, why shouldn’t I? Italy has not been of any help to us and Spain has been horrible, absolutely horrible.”

His announcement on tariffs also comes a week after the European Commission vice-president, Maroš Šefčovič, made a three-day trip to Washington, meeting all the relevant senior figures in Trump’s administration, including the commerce secretary, Howard Lutnick, the US trade representative, Jamieson Greer, and the treasury secretary, Scott Bessent. It was the first trip Šefčovič had made since the July EU-US tariff deal was signed.

The news also comes weeks after the European parliament voted to ratify the deal, having twice paused the formal process.

In January MEPs formally suspended the process in protest at Trump’s threat to take over Greenland from Denmark, and in February the parliament paused the voting procedure following an adverse US supreme court ruling.

Although the 15% tariff deal was ruled illegal by the supreme court earlier this year, the tax on cars was imposed under separate legislation known as section 232 of the Trade Expansion Act.

The Turnberry deal in Scotland agreed a 15% tariff on imports from the EU on most goods, including cars, which were then facing tariffs of 50% on exports to the US.

Following heavy lobbying from the EU, the German car manufacturers and words from the German chancellor, Friedrich Merz, Trump relented, agreeing to include cars in the 15% baseline all-inclusive tariff rate.

But 50% tariffs on steel continued and, as a quid pro quo, the EU agreed to buy $750bn of energy from the US and make $600bn investment in the US.

The EU has been approached for a response.