Stocks closed lower after a volatile day of trading, with automakers and banks among big losers, after President Trump hit Mexico, Canada and China with tariffs, prompting pushback from all three countries.

Beijing, Mexico City and Ottawa reply in kind to Washington, Minnesota’s agricultural exports will likely become more expensive and thus less competitive on the world market," John Rash writes. (Glen

China and Canada are fighting back as new U.S. tariffs take effect against those countries and Mexico. Beijing swiftly announced 15% retaliatory tariffs on some American goods. Canada says Ottawa will immediately respond with tariffs on $30 billion of U.

Amid concerns over a trade war, US President Trump has suspended 25% tariffs on Canada and Mexico imposed earlier this week.

The tariff actions, which could upend nearly $2.2 trillion in two-way annual U.S. trade, went live hours after Trump declared that all three countries had failed to do enough to stem the flow of the deadly fentanyl opioid.

The federal government has put together a $6.5-billion aid package and is making temporary changes to the employment insurance program to support Canadian businesses and workers through the trade war with the United States.