Washington/Ottawa , Aug. 22 -- Trade war between the United States and Canada flared anew on Saturday after last-minute negotiations collapsed, clearing the way for new US tariffs of up to 50 per cent on billions of dollars of Canadian goods and prompting Prime Minister Mark Carney to pledge matching measures against U.S. imports.

Carney said Canada had suspended trade talks with Washington after late changes to proposed US terms were deemed "unfair" and "uneconomic," ending hopes of a deal just hours before the midnight deadline.

"As a result, this evening, I have decided to suspend trade negotiations with the US and have directed Canada's negotiators to return to Ottawa," Carney said in a statement.

"Canada will match those tariffs dol...