Major stock indexes were slightly lower on Friday as U.S. President Donald Trump's announcement of tariffs on imports from Canada fanned worries about trade tensions, with the Canadian dollar down against the greenback.

President Donald Trump threatened a 35% tariff on some Canadian goods and raised the prospect of increasing levies on most other countries, ramping up his trade rhetoric in comments that weighed on stocks and boosted the US dollar.

Trump threatened to escalate tariffs beyond 35% if Canada opts to retaliate with tariffs on U.S. goods. Canadian goods are also subject to sector-specific tariffs, such as 50% levies on steel and aluminum as well as 25% tariffs on non-USMCA compliant autos and auto parts.