The U.S. imposed a 25% tariff on Canadian goods on Sunday as part of an executive order aimed at stemming the flow of illicit drugs across the country’s northern border. The order, expanding a declared national emergency, targets Canada’s alleged role in the U.S. fentanyl crisis. The U.S. also imposed tariffs on Mexico and China.

In response, Canada’s finance and foreign ministers announced countermeasures amounting to a $155 billion tariff package on U.S. goods, effective Feb. 4. The measures, described as a defense of Canadian interests against what officials labeled as unjustified U.S. tariffs, include phased tariffs on a broad array of products ranging from consumer staples to industrial inputs. Meanwhile, Beijing announced it would challenge the tariff at the World Trade Organization and take unspecified countermeasures.