By Ana Swanson

New York Times News Service

WASHINGTON — The United States and the European Union are preparing to impose tit-for-tat tariffs on each other’s products, the latest escalation in a 14-year fight over government aid given to Boeing and European rival Airbus.

“The World Trade Organization finds that the European Union subsidies to Airbus has adversely impacted the United States, which will now put Tariffs on $11 Billion of E.U. products!” President Donald Trump said in a tweet Tuesday morning. “The E.U. has taken advantage of the U.S. on trade for many years. It will soon stop!”

The office of the U.S. trade representative said Monday night that it was preparing a list of European products to tax as retaliation for European subsidies to Airbus, which the World Trade Organization ruled were illegal in May 2018.

That prompted the European Union to announce that it was readying a list of tariffs to counter U.S. subsidies to Boeing.

The moves come amid tense trade relations between the United States and Europe, which are engaged in a battle of tariffs after Trump’s decision last year to tax European steel and aluminum. Trump has repeatedly threatened to impose tariffs on European cars and car parts if the European Union does not agree to better trade terms for U.S. products, and Europe has said it will retaliate on U.S. goods if Trump follows through on that threat.

The announcement of new tariffs stems from a dispute that began in 2004 related to government subsidies that Europe provides to Airbus.

Last May, the WTO found that Airbus had received illegal funding for several of its aircraft models.

The United States requested the authority to impose retaliatory tariffs of $11.2 billion per year, and the two sides are awaiting a decision on the level of tariffs that the United States will be authorized to levy on the European Union.

In preparation for that decision, which is expected this summer, the United States announced Monday night that it was beginning to identify European products to tax, so it could impose the duties as soon as the organization ruled. The initial list would cover $11 billion of trade in products, including airplanes, cheese, fish, wine, clothing, nails, pipes and clocks — the same dollar amount of harm that the U.S. trade representative estimated European subsidies cause each year.

“This case has been in litigation for 14 years, and the time has come for action,” Robert Lighthizer, the U.S. trade representative, said in a statement.

“Our ultimate goal is to reach an agreement with the EU to end all WTO-inconsistent subsidies to large civil aircraft,” Lighthizer said. “When the EU ends these harmful subsidies, the additional U.S. duties imposed in response can be lifted.”

The European Commission indicated Tuesday that it considers the $11 billion in retaliatory measures to be overblown and not justified by any findings by the World Trade Organization.

“The figure quoted by the U.S. trade representative is based on U.S. internal estimates that have not been awarded by the WTO,” Daniel Rosario, a European Commission spokesman, said during a press briefing in Brussels on Tuesday, reading from a prepared statement.

In a statement, Airbus called the U.S. tariff announcement “totally unjustified” and said that the European Union would take “far larger countermeasures against the U.S.”

Rosario said the commission, the European Union’s administrative arm, would ask WTO arbitrators to authorize retaliatory measures, which would be in response to a WTO finding last month that Boeing received tax breaks in Washington state and incentives in South Carolina that amounted to subsidies.

The European Commission has begun drawing up a list of products that would be covered by retaliatory tariffs, but is awaiting a WTO decision before specifying which products would be targeted and how much trade they would encompass.

In a statement, Boeing said it supported the U.S. trade representative and hoped that the draft tariff list would encourage the European Union “to comply with past WTO rulings against it” and “end all illegal government support for Airbus.”

The United States’ arguments at the WTO have centered on billions of dollars of “launch aid” that the European Union has given Airbus to develop new products. The United States has long argued that such aid gave Airbus an unfair advantage, allowing it to gain market share in Europe, Australia, China, South Korea and elsewhere at Boeing’s expense.

European criticism of the U.S. aviation sector has mostly focused on government research contracts granted to Boeing through agencies like the Defense Department and NASA, as well as tax breaks at the federal, state and local levels.