OTTAWA—Canada’s economy picked up the pace of growth in the first three months of the year as businesses braced for the disruption of a bruising trade war with the U.S., though domestic activity weakened and hints at what lies in store in the new tariff era.

Canada's economy grew faster than expected in the first quarter, data showed on Friday, primarily driven by exports as companies in the United States rushed to stockpile Canadian goods before President Donald Trump's tariffs were implemented.