0420 GMT July 17, 2019
"Today, the Office of the US Trade Representative is issuing for public comment a supplemental list of products that could potentially be subject to additional duties," it said in a statement, AFP reported.
The potential tariffs are due to "EU subsidies on large civil aircraft," the statement said.
"This supplemental list adds 89 tariff subheadings with an approximate trade value of $4 billion to the initial list published on April 12, which included tariff subheadings with an approximate trade value of $21 billion," it added.
For more than 14 years, Washington and Brussels have accused each other of unfairly subsidizing aviation giants Boeing and Airbus, respectively, in a tit-for-tat dispute that long predates US President Donald Trump's time in office.
The Boeing-Airbus spat is the longest and most complicated dispute dealt with by the World Trade Organization, which aims to create a level playing field in global trade.
Trump has made taking aim at what he views as unfair trade practices that disadvantage the US a key goal of his presidency, and tariffs are his favored tool for doing so.
EU governments were shell-shocked last year when Trump imposed tariffs on metals imports as part of his “America First” protectionist vision.
Brussels responded by slapping counter-tariffs on more than $3 billion in US exports like blue jeans and Harley-Davidson motorcycles.
The latest chapter in the US-EU trade spat comes amid a trade war between Washington and Beijing that has seen the two sides impose tariffs on hundreds of billions of dollars in two-way trade.