Hong Kong (CNN Business) The United States is intensifying its trade fight with the European Union over aircraft subsidies , proposing new tariffs on EU goods worth $4 billion.

They could be added to a list of EU exports worth $21 billion that the USTR said in April would be subject to tariffs.

The threat to target more European goods comes just days after the United States and China agreed to resume talks on a trade deal. President Donald Trump said he would hold off imposing new tariffs on China.

Washington has been locked in a dispute with the European Union for years over two of the world's biggest airplane manufacturers —and

The conflict dates back to 2004, when EU authorities said Boeing received $19 billion in unfair subsidies from federal and state governments between 1989 and 2006. The US government filed a similar claim that year over European subsidies to Airbus.

The World Trade Organization has handed down favorable rulings to both sides since then, underscoring the complexity of the dispute.

The tariffs proposed by the Trump administration are subject to public consultation in the United States and arbitration at the WTO, which is expected to deliver its findings this summer.

A spokesman for the European Commission said it had noted the latest move by the United States. The spokesman added that Europe could retaliate in the Boeing case.

"The European Union remains open for discussions with the United States, provided these are without preconditions and aim at a fair outcome," the spokesman said.

US spirits industry upset

The taxes proposed by the Trump administration were criticized by the Distilled Spirits Council of the United States, which objected to the inclusion of Scotch and Irish whiskey.

"These tariffs, if imposed, will have numerous unintended negative consequences on US jobs, US consumers and on US companies that export to the European Union," it said in a statement.

"US companies — from farmers, to suppliers to retailers — are already being negatively impacted by the imposition of retaliatory tariffs by key trading partners on certain US distilled spirits resulting from other trade disputes, and these additional tariffs will only inflict further harm," it added.

The threat is the latest in a series of trade clashes between the United States and the European Union. The Trump administration has already imposed tariffs on European steel and aluminum, to which EU authorities responded with tariffs on US goods worth more than $3 billion.

Trump has also threatened to slap tariffs of up to 25% on cars coming into the United States, a move that could hit European automotive powerhouses like Germany and France.

The trading relationship between the two sides is worth more than $1 trillion annually, but Europe exports significantly more goods to the United States than the other way around.

The escalation of trade tensions with one major US trading partner comes days after a truce with another