President Donald Trump posted a letter to social media Thursday evening announcing Canadian goods will be subject to a 35% tariff rate starting Aug. 1

Canada faces another set of tariffs in its ongoing trade talks with the U.S. However, in this latest round of tariff announcements, investors have learned to largely tune them out as negotiating bluster rather than policy commitments.

President Donald Trump late Thursday threatened a 35% tariff on goods imported from Canada, a dramatic escalation in an on-again, off-again trade war with America’s northern neighbor and one of its most important trading partners.