In response, Mr. Trump said on Truth Social late Thursday the U.S. would decertify all Canadian aircraft, including planes from its largest aircraft maker, Quebec-based Bombardier. Mr. Trump said he is "hereby decertifying" the Bombardier Global Express business jets and "all Aircraft made in Canada." If Mr. Trump cuts off the U.S. market, it would be a major blow to the Quebec company. The U.S. and Canada have faced off over trade and tariffs since Mr. Trump's return to the White House last year. Besides Bombardier, other major aircraft manufacturers in Canada include De Havilland Aircraft of Canada, which makes turboprop planes and aircraft designed for maritime patrols and reconnaissance, and European aerospace giant Airbus.