Global markets buckled up for a turbulent session on Monday after U.S. President Donald Trump launched a trade war with sweeping tariffs on Canada, Mexico and China that threaten to undermine economic growth and reignite inflation.

Trump positioned the tariffs as a way to “halt the flood of poisonous drugs into the United States,” referring to fentanyl. The change will have a big impact on the cost of a wide variety of goods imported from each country, including electronics, produce, clothing, and much more.

U.S. stock-index futures were expected to open lower Sunday night after President Donald Trump announced heavy tariffs on imports from Canada, Mexico and China, as investors braced for volatility across financial markets.