President Donald Trump's administration has announced it will raise the import tariff on EU aircraft from 10 to 15% in March.
It's mainly targeted at giant European plane manufacturer Airbus.
The 10% tariff was introduced back in October after the World Trade Organisation (WTO) ruled the US could legally impose tariffs worth €6.9 billion.
That was because the EU had been caught illegally subsidising Airbus, according to WTO.
But the WTO has also ruled that the US were guilty of subsidising its own giant aircraft manufacturer, Boeing.
In the coming months, it will rule on what level of tariffs the EU can legally impose.
Since the ruling in October, the US has also slapped a 25% tariff on other EU products including wine, cheese, coffee and olives.
Airbus has said it "deeply regrets" the tariff, which it believes will only increase trade tensions between the EU and the US.
It says it hopes the US will reconsider when the WTO rules against Boeing.