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.

Canada and Mexico ordered retaliatory tariffs on American goods in response to sweeping tariffs imposed by President Donald Trump, and businesses and consumers in both countries questioned Sunday how the new trade war might affect them.

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.

Prime Minister Justin Trudeau set out "far-reaching" tariffs of 25%, affecting 155bn Canadian dollars' worth ($106.6bn; £86bn) of American goods ranging from beer and wine, to household appliances and sporting goods.

The crossing between Detroit and Windsor, Ontario, is a flashpoint in the new trade war between the U.S. and Canada that will have a big impact on the auto industry

The trade penalties that Trump signed Saturday at his Florida resort caused a mix of panic, anger and uncertainty, and threatened to rupture a decades-old partnership on trade in North America while further straining relations with China.

Donald Trump hit Canada, Mexico and China with steep tariffs on Saturday, and oil and gas groups are relying more heavily on carbon offsets to reach climate targets. Plus, EU governments are exploring ways to include the UK and Norway in a “coalition of the willing” dedicated to ramping up the continent’s defence.

President Donald Trump said Sunday that Americans could feel “some pain” from the emerging trade war triggered by his tariffs against Canada, Mexico and China, and claimed that Canada would “cease to exist” without its trade surplus with the United States.

Investors bought dollars, sold stocks and fretted about inflation on Monday in a scramble to assess the risk of trade war after Donald Trump put tariffs on top U.S. trading partners.