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.

The president’s trade assault, which makes no distinction between ally and adversary, is an assertion of U.S. dominance with significant risks.

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.

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.

President Donald Trump has signed an order to impose stiff tariffs on imports from Mexico, Canada and China, drawing swift retaliation from the U.S.’s North American neighbors in an emerging trade war.