If there are ready substitutes for imported goods, the importer has little ability to pass on the price increase to consumers," an economist said.

Trump has promoted the tariffs as part of a wider strategy to revive American manufacturing, and as a way to extract concessions from the U.S.' trading partners, adversaries and allies alike. "No room left for Mexico or Canada,

Major stock indexes fell in volatile trade on Tuesday, with the Nasdaq Composite index at one point down 10% from its December record high, while Treasury yields also seesawed as the United States hit Canada,