The stock market fell on Monday after President Donald Trump slapped tariffs on Canada, Mexico and China, eliciting threats of retaliation and setting the stage for a trade war.

The Dow Jones Industrial Average slid about 550 points, or 1.25%, in early trading on Monday. The S&P 500 dropped 1.5%, and the tech-heavy Nasdaq plummeted 2%.

Traders demonstrated their jitters with a selloff of U.S. auto companies, which hold deep ties to suppliers in Canada and Mexico. Shares of General Motors plummeted 7.5%, while Ford saw its stock price plunge 4.5%.

The market rout extended worldwide. Japan’s Nikkei index fell 2.5% on Monday, and the pan-European STOXX 600 dropped about 1%.

This is a developing story. Please check back for updates.