President Donald Trump said this weekend that critics of his tariffs are controlled by China or other countries, taking special aim at the Wall Street Journal after an editorial called his tariffs "the dumbest trade war in history.

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.

The U.S. stock markets have tanked after an early selloffs over fears of President Donald Trump’s new tariffs on Canada, Mexico and China. Trump delivered on his threats to introduce trade tariffs on the nations in a move that has sparked panic across global financial markets.