Buffett has previously expressed concerns about tariffs, opposing Trump's trade proposals during the 2016 campaign, when he called them "a very bad idea"

Warren Buffett, the famed investor behind Berkshire Hathaway, offered a sharp rebuke of President Donald Trump’s 25-percent tariff on goods from Mexico and Canada set to take effect Tuesday. “They’re an act of war to some degree,

Warren Buffett says tariffs are “an act of war, to some degree.” Berkshire Hathaway’s chairman and chief executive said the country has had a lot of experience with tariffs, and that over time they are a tax on goods.