U.S. stocks endured another serious setback on Monday as what one trader described as a tariff “tape bomb” from President Trump caused the S&P 500 to tally its biggest daily drop in months.

U.S. stocks are falling sharply after President Donald Trump said tariffs he announced on Canada and Mexico will take effect at the end of the day.

Consumers in the US could see price hikes within days, an expert has said, adding "the automobile sector, in particular, is likely to see considerable negative consequences".