The move could ease costs for American businesses and farmers that depend on Canadian supplies, particularly in Maine, a state where Democrats are hoping to win.
US President Donald Trump has lifted 50% tariffs on some Canadian imports, two weeks before the midterm elections, following pressure from Republican Senator Susan Collins, who is facing a tough re-election contest in Maine.
The White House said on Friday that the exemptions cover products including plywood sheets, paper goods, certain machinery, refrigeration equipment and packing materials.