Donald Trump’s plan to realign global trade faces its latest legal barrier this week in a federal appeals court — and Canada is bracing for the U.S. president to follow through on his threat to impose higher tariffs.

A slew of countries will face steep levies, including a 50% tariff on imports from Brazil and a 30% tariff on the European Union.

Trump recently said he will impose a 35% tariff on Canada, the latest salvo in his on-again, off-again trade war with the U.S. ally and top trade partner.

The possibility of a 30% tariff this week “is a game changer,” said Dante Galeazzi, CEO and president of the Texas International Produce

The letter reiterated Trump’s complaints about dairy quotas, fentanyl and the U.S. trade deficit, which is mostly fueled by American refineries’ thirst for Canadian oil. His social media post caused the Canadian dollar to immediately tumble, indicating the market wasn’t expecting this escalation.

Canada is one of the United States' top trading partners, with more than $410 billion of goods crossing into the country last year.

Canada's retail sales shrank by 1.1% in May as consumers curtailed car purchases and spent less at supermarkets, convenience stores and on alcohol, data showed on Thursday.

President Donald Trump’s vows to roll out punishing new tariffs on Aug. 1 have barely made a ripple with investors who are convinced he’ll once again back down. But at the White House, officials insist they’re serious this time.