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.

Leavitt told reporters in her first White House press briefing that Trump also is still "very much" considering fresh tariffs on China for Saturday. Shortly after taking office last week, Trump set a Feb.