U.S. President Donald Trump added fuel to his feud with Harley-Davidson Inc. by claiming he's working with other motorcycle-makers to offset the production it's shifting overseas.

He'll almost certainly have to work with foreign companies to do so, and none has stepped forward to announce any such negotiations.

"Now that Harley-Davidson is moving part of its operation out of the U.S., my Administration is working with other Motor Cycle companies who want to move into the U.S." Trump tweeted Tuesday. "Harley customers are not happy with their move — sales are down 7% in 2017. The U.S. is where the Action is!"

Harley's rivals in its domestic market include Honda Motor Co., Yamaha Motor Co., Kawasaki Heavy Industries Ltd. and Suzuki Motor Corp. The only major U.S. motorcycle manufacturer other than Harley is Polaris Industries Inc., and a spokeswoman for the company told the Associated Press last week that it might move some Indian-brand motorcycle output to Poland from Iowa in order to avoid European Union tariffs.

Honda hasn't had any discussions with the Trump administration about motorcycle production, spokesman Lee Edmunds said. Germany's BMW AG, which makes the majority of its bikes at a factory in Berlin, hasn't been approached either, spokesman Kenn Sparks said. Kawasaki declined comment, and representatives for the other companies didn't respond to inquiries.

Trump has sent half a dozen tweets attacking Harley since the company said last week that taxes the EU has slapped on its bikes in reaction to U.S. steel and aluminum levies will cost as much as $100 million a year. The Milwaukee-based manufacturer that Trump praised last year as "a true American icon" plans to shift some production out of the U.S. to unspecified overseas plants over a nine- to 18-month period.