The latest battle in U.S. President Donald Trump’s trade war is highlighting how the Canadian province of Ontario provides electricity to some American homes and businesses.

But Trump announced time was up on March 3, and the tariffs went into effect overnight. Stock markets slipped, Canada ordered reciprocal tariffs, and by Thursday, Trump gave another 30-day extension to goods covered under the United States-Mexico-Canada Agreement, which applies to approximately 38% of imports from Canada.

Ontario’s premier said the tariff would remain in place despite the one-month reprieve from President Trump, noting a one-month pause means nothing but more uncertainty.