WASHINGTON, D.C.: The threat to impose a 50 percent tariff on any Canadian aircraft sold in the United States is the latest salvo in U.S. President Donald Trump's escalating trade war with Canadian Prime Minister Mark Carney.  

Posted on social media, Trump's latest threat came after his earlier warning of imposing a 100 percent tariff on goods imported from Canada if Carney went ahead with a planned trade deal with China.

This time, the Republican president said he was retaliating against Canada for refusing to certify Gulfstream Aerospace jets, based in Savannah, Georgia.

"If, for any reason, this situation is not immediately corrected, I am going to charge Canada a 50 percent tariff on any and all aircraft sold into the United States of America," Trump said in his post.

Trump said he was "decertifying" Bombardier's Global Express business jets. About 150 of these aircraft are registered in the United States and are operated by 115 different companies, according to aviation data firm Cirium.

The U.S. Commerce Department had earlier imposed duties on a Bombardier passenger jet in 2017, during Trump's first term, saying the company was selling planes in the U.S. for less than what it costs to make them. At the time, the U.S. government accused the manufacturer of using unfair government subsidies to keep prices artificially low.

However, the U.S. International Trade Commission later ruled that Bombardier did not harm American industry.

Since then, Bombardier has focused on business and private jets. If Trump blocks access to the U.S. market, it would be a significant blow to the Quebec-based company.

Treasury Secretary Scott Bessent warned Prime Minister Mark Carney earlier this week that his recent public criticism of U.S. trade policy could have negative consequences, especially as a formal review of the U.S.–Mexico–Canada Agreement begins. That trade deal helps shield Canada from the worst effects of Trump's tariffs.

Canada is also home to other major aircraft makers, including De Havilland Aircraft of Canada, which builds turboprop planes for patrol and surveillance, and Airbus. The European company produces its A220 passenger jets and helicopters in Canada.

Under the Biden administration, U.S. trade officials highlighted how closely linked the American and Canadian aerospace industries are. They pointed to a 1980 World Trade Organization agreement that requires countries to remove tariffs on civilian aircraft, engines, simulators, and related parts.

Canada's Trade Commissioner Service says the United States is the largest market for Canada's aerospace and space industries and a key destination for exports of aircraft, components, and space technology.