A report in WirtschaftsWoche cites unnamed diplomatic sources who say Trump told French president Emmanuel Macron he would maintain his trade policy “until no Mercedes models rolled on Fifth Avenue in New York.” The trade policy would seemingly affect any German automaker, though, putting sales of Porsche and Volkswagen (and its Audi luxury division) at risk as well as Daimler.

Trump began pushing for heavy tariffs (as much as 25%) on car imports a week ago. U.S. Commerce Secretary Wilbur Ross said at the time “there is evidence suggesting that, for decades, imports from abroad have eroded our domestic auto industry.”

Trump himself hinted at the news before the announcement, implying the tariffs would result in more domestic jobs for automakers.

There will be big news coming soon for our great American Autoworkers. After many decades of losing your jobs to other countries, you have waited long enough!

— Donald J. Trump (@realDonaldTrump) May 23, 2018

WirtschaftsWoche did not offer additional details about how Trump planned to block sales. Germany, though, is the largest European exporter of cars to the United States.

Trump has long held a hardline position toward German automakers. Last January, he underscored this in comments that appeared in the German magazine Bild.

“When you walk down Fifth Avenue, everybody has a Mercedes-Benz parked in front of his house,” Trump said, according to a Wall Street Journal translation of the comments. “You were very unfair to the U.S.A. It isn’t mutual. How many Chevrolets do you see in Germany? Not many, maybe none, you don’t see anything at all over there. It’s a one-way street.”