President Donald Trump said the sweeping tariffs that he has imposed on Mexico, Canada and China may cause "short term" pain for Americans as global markets reflected concerns the levies could undermine growth and reignite inflation.

Amid warnings of price increases, Canada moved quickly to retaliate, China said it had planned countermeasures and Mexico said it would soon unveil its response.

Shares of auto giants fell sharply on Monday as U.S. President Donald Trump imposed long-threatened tariffs on goods from Canada, Mexico and China. Analysts expect Trump's tariffs to have a profound impact on the global automotive industry,