Trump has vowed punishing tariffs on Mexico, Canada and China, which are Texas’ biggest international trading partners.

The stakes are particularly high for Texas and other border states, where trade with Mexico is worth hundreds of billions of dollars a year.

Roughly $900 billion in annual trade between Canada and the United States — and with it, traditionally chummy bilateral ties — is on the brink of upheaval, with President Donald Trump threatening to impose sweeping tariffs on Canada as early as this weekend.