US President Donald Trump is invoking a 1930 trade law to impose whopping 50 percent tariffs on certain Canadian goods.The move threatens a broader trade war with the United States' second-top trading partner.The impacted Canadian goods range from electric equipment, such as refrigeration, to machinery, according to annexes of three proclamations Trump signed on Monday (local time).The tariffs wouldn't take effect for 30 days.Trump cited Section 338 of the Tariff Act of 1930, a law that allows a president to tariff goods up to 50 percent without congressional approval when a country is believed to be discriminating against American goods.However, the law has never been applied this way.Last week, Trump threatened higher tariffs on Canadian goods to punish the country for the impact its wildfires have had on Americans in recent days.However, a senior administration official told reporters on Monday that this action was unrelated."The president has other options on that," the official said.Rather, the latest tranche of tariffs was related to alleged discriminatory treatment of American motor vehicles, alcohol and dairy.- CNN