Stock futures tumbled Sunday night to kick off a new trading month, as investors weighed new U.S. tariffs on goods from key trade partners and their potential impact on the economy and corporate profits.

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.

A day after levying steep new tariffs on Mexico, Canada and China, President Trump acknowledged what economists, members of Congress and even some of his own aides — in their previous lives — have been saying all along: Americans may find themselves paying the costs.

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

Trump has said tariffs are a way to force the countries to stop the flow of migrants and fentanyl across the borders and into the U.S.

President Donald Trump has taken executive action to impose new tariffs on imports from Canada, China and Mexico

China's sharpest pushback on Sunday was over fentanyl, an area where the Biden administration had also been urging Beijing to crack down on shipments.

Trump knows the United States has more leverage over its neighbors than they do over his country. But exploiting that position of strength could cause a historic rupture.

Prime Minister Justin Trudeau says Canada is ready to respond with 25 percent tariffs against C$155 billion worth of American goods.