Danish Prime Minister Mette Frederiksen is one of several EU leaders who early on Monday warned of measures to counter the trade threats from US President Donald Trump.
If the US imposes a tariff, we cannot do anything but respond strongly, says Frederiksen in connection with the EU countries' summit in Brussels.
And Commission President von der Leyen emphasizes that the EU is ready to respond.
If we are unfairly or arbitrarily attacked, the EU will respond with firmness. These tariffs increase costs for companies and harm workers and consumers. We do not see much good in them, she says at the press conference afterwards.
"Bad politics"
Even Prime Minister Ulf Kristersson (The Moderate Party) sees it as given that the EU will respond jointly. But he still hopes that there will be no tariffs, with the help of purely economic arguments.
Tariffs are basically just bad. Imposing tariffs on each other is bad economic policy that no one will benefit from in the long run, says Kristersson - and points out that there are others to trade with than the US.
We are a large block of 450 million people who have our own free trade and want as much free trade as possible with other parts of the world. The US is important, but the world is even bigger. So, there are reasons why we are now concluding new free trade agreements between Europe and other large and small continents, says the Prime Minister in Brussels.
China laughing?
If, despite everything, a decision comes from Trump, the EU is expected to respond with its own tariffs - primarily targeting goods produced in parts of the US where President Trump has some of his strongest supporters.
American bourbon, motorcycles, and orange juice from Florida are some examples that may come into question.
At the same time, many EU leaders are still holding out hope that it will not have to go that far.
If the US starts a trade war, it is China that will laugh, warns EU Foreign Minister Kaja Kallas.
Germany's Chancellor Olaf Scholz smiles slightly crookedly when asked how he views Mexico's response to the US tariffs and got a one-month reprieve.
The Mexican President (Claudia Sheinbaum) is a very wise politician. She has acted coolly, says Scholz after the summit in Brussels.
The EU countries' heads of state and government are holding an informal summit at the Egmont Palace in Brussels on Monday.
The leaders are discussing primarily defense issues, how the EU can jointly strengthen its defense and how it should be financed. The meeting is not expected to lead to any immediate decisions, but only pave the way for measures later this year.
NATO Secretary-General Mark Rutte is invited as an extra guest during lunch, while the UK's Prime Minister Keir Starmer is present as a dinner guest.