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.

By David Lawder WASHINGTON (Reuters) - President Donald Trump has pushed into new trade law territory with an emergency sanctions law to justify punishing 25% tariffs on Canadian and Mexican imports and an extra 10% duty on Chinese goods to curb fentanyl and illegal immigration into the U.

Robert Lighthizer, who was the U.S. trade representative in President Trump's first administration, says China poses an existential threat to the United States that must be urgently addressed by Washington.