TORONTO — 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.

He noted those tariffs were separate from a broad effort by the Commerce Department, the U.S. Trade Representative’s office and the Treasury Department to review trade relations and tariffs by April 1.