The National Post reports in its Saturday edition that U.S. President Donald Trump said 50-per-cent tariffs targeting Canada's aircraft sector was prompted by a complaint from a friend who couldn't buy the corporate jet of his choosing. Postmedia's Swikar Oli writes that Mr. Trump made the remark Wednesday during a six-minute-long rant about Canada in the Oval Office. "I had a case about a week ago, where a friend of mine was buying a Gulfstream jet, and he said: 'You know, it's a crazy thing. We're not able -- that Canada won't certify Gulfstream,'" Mr. Trump said. "Gulfstream is the best private jet, you know, the best of the best," he said, adding Canada "won't certify it because they make a competitor, Bombardier Global Express." The unprompted remark appeared to be a glimpse into what was behind his threat to decertify Canadian-made aircraft and impose 50-per-cent tariff on sales back in January. The friend was close to Gulfstream, Mr. Trump said, and had asked the headof the company to arrange a call with him and explain the situation. In February, Transport Canada granted regulatory approval to two business jets produced by Gulfstream. It came nearly four weeks after Trump had threatened to decertify Bombardier.