According to Trump, tariffs will be raised to 25 percent from the current roughly 15 percent.
The reason, according to Trump, is that "the European Union is not following our fully agreed trade agreement."
It is unclear what the president means by the EU violating the agreement.
It was on March 26 that the EU Parliament gave its approval to the trade agreement with the US, after delaying it following Trump's threat to take over Greenland.
According to the agreement, in addition to setting tariffs, the EU will increase investments across the Atlantic.
Reduce the level of conflict
The agreement has still not been finally ratified at EU summit level. Negotiations are underway to align the Council of Ministers' position with that of the Parliament, and the next meeting is scheduled for 6 May.
Benjamin Dousa (M) writes to TT that the government is working to reduce the level of conflict.
"The EU needs to quickly fulfill our part, and so does the US. We do not want new trade conflicts, especially when it risks affecting an important Swedish export industry such as vehicles," he writes.
A spokesperson for the European Commission writes that Washington is being kept updated on the Union's process, and is also seeking information about the US process.
The EU is working for "a predictable, mutually beneficial transatlantic relationship" but if the US does something that contradicts the intentions of the intended agreement, "we will keep our options open to protect the EU's interests," it says.
After March 26, several European decision-makers, including the President of the European Parliament, Roberta Metsola, pointed out that time will tell whether the United States can be trusted.
Trump also emphasizes in his post on Truth Social that cars and trucks produced in American factories are not subject to tariffs.
Stellantis slumps
He then writes that over $100 billion has been invested by foreign companies in automotive factories in the United States and that they will soon provide many jobs in the country.
BMW, Mercedes-Benz, Volkswagen, Volvo Cars and Volvo Trucks, among others, have factories in the United States.
It's worse for the automotive group Stellantis, which imports Alfa Romeo, Fiat and Maserati models to the US from Europe.
Stellantis' shares on the New York Stock Exchange fell after Trump's announcement and, an hour later, were down 2.3 percent for the day.
