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 says he's prepared to tariff and punish countries that challenge the U.S. dollar as the global reserve currency.

Many economists already believe it’s a matter of time before Americans start to see sticker shock from the tariffs President Donald Trump has enacted. That timeline could speed up even more if Trump follows through with his latest package of tariff threats slated to take effect in three weeks.

President Donald Trump's antitrust enforcers recently cleared a string of multibillion-dollar deals in a week, demonstrating a willingness to settle with companies that marks a shift from the Biden administration.