By Ramishah Maruf, Chris Isidore, CNNNew York (CNN) — President Donald Trump said on Thursday that he is decertifying all aircraft made in Canada and threatened a 50% tariff on those planes until American-made Gulfstreams are certified in that country. Just hours earlier, Canadian Prime Minister Mark Carney said he expects Trump to “respect Canadian sovereignty” after reports that Alberta separatists met with US officials. And a few days earlier, Trump threatened a 100% tariff on America’s second-biggest trading partner if it struck a trade deal with China. It is unclear whether Trump has the legal authority to decertify aircraft; the White House has not released an executive order on any Canadian aircraft tariffs. “Using aircraft safety as a tool in a trade war is just an incredibly bad idea,” he said.