New Delhi, Aug. 23 -- The talks were supposed to buy time. When the United States extended its tariff deadline by three days last week to allow negotiations, both governments privately signaled a deal was possible. By early Saturday, both governments had acknowledged it was not.

"They asked too much and offered too little." US Trade Representative Jamieson Greer, in a statement released hours later, said Washington was "moving forward with measures that respond to Canadian retaliation" and confirmed there were "no new planned talks."

The 50% tariffs - targeting roughly $20 billion in Canadian goods, about 5% of Canada's annual exports to the United States - went into effect early Saturday morning. Trump deployed Section 338 of the Smoot...