flickr/White HousePrime Minister Mark Carney said Wednesday that Canada’s negotiations with the United States might not conclude by Donald Trump’s Aug. 1 deadline, as the president added new trade measures that could further hinder some Canadian businesses. Trump sent a letter to Carney threatening to impose 35% tariffs if Canada doesn’t make a trade deal by Friday. In a separate order, Trump suspended de minimis exemptions — which had allowed packages worth US$800 or less to ship to the United States tariff-free. As part of his reasoning for the change, Trump cited the flow of fentanyl into the United States. The latest trade changes come as countries around the world are set to face staggering tariffs when Trump’s deadline to make deals passes.