Steelmakers in the U.S. saw their share rise Thursday, May 31, after U.S. Commerce Secretary Wilbur Ross announced the U.S. government will begin imposing steel and aluminum tariffs on the European Union, Canada and Mexico.

Ross said a 25% tariff on steel imports and a 10% tariff on aluminum imports would go into effect on Friday, June 1.

When the market closed on Thursday, United States Steel Corp. (X) - Get Report   was up nearly 2%, AK Steel Holding Corp. (AKS) - Get Report was down 1.3%, Nucor Corp. (NUE) - Get Report  was up slightly, and Reliance Steel and Aluminum Co. (RS) - Get Report was down nearly 1%.

"Trump has brought uncertainty, and the market dislikes uncertainty," said Hugo Perezcano, deputy director of economic law at the Centre for International Governance Innovation.

Perezcano also added that he "doesn't see tensions easing" thanks to the tariffs. 

Canada announced that it was planning on issuing retaliatory tariffs that would go into effect in July. Both the EU and Mexico have spoken out against the tariffs, but neither of them have issued tariffs yet. 

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