The European Union immediately said it would impose countermeasures in response to the U.S. actions.

Those entities had been exempt from the 25 percent tariffs on steel imports and 10 percent tariffs on aluminum imports.

The Trump administration is putting steel and aluminum tariffs on U.S. allies Canada, Mexico and the European Union.

The Trump administration will put tariffs on steel and aluminum imports from Canada, Mexico and the European Union, the latest action in a string of protectionist policies to crack down on alleged trade abuses. The tariffs of 25 percent on steel imports and 10 percent on aluminum imports will take effect at midnight Thursday, Commerce Secretary Wilbur Ross told reporters. The U.S. gave those allies a reprieve from the duties, but the exemptions were set to expire Friday. The Trump administration will place quotas or volume limits on other countries such as South Korea, Argentina, Australia and Brazil instead of tariffs, he said. Condemnation from U.S. allies poured in immediately Thursday. European Commission President Jean-Claude Juncker called the tariffs "unjustified" and said the EU will introduce countermeasures in the coming hours. A spokesperson for the British government also said the U.K. is "deeply disappointed" in the move and added U.S. allies "should be permanently and fully exempted" from the tariffs. Mexico also said it would impose tariffs in response to the U.S. actions. The Trump administration move is only its latest in a series of actions targeting foreign countries' trade practices that escalates the chances of a trade war with major world economies. Trump has repeatedly promised to crack down on trade habits that he says harm American companies and sap U.S. jobs.

In a proclamation announcing the measures, Trump wrote that he agreed with Ross' "finding that steel mill articles are being imported into the United States in such quantities and under such circumstances as to threaten to impair the national security of the United States." American steel and aluminum producers have cheered the Trump administration's metals tariffs, and shares of companies such as U.S. Steel and AK Steel surged Thursday. Meanwhile, the prospect of more protectionism led the Dow Jones industrial average and to hit their lows for Thursday trading after the news. The U.S. dollar also approached a session high against the Canadian dollar and Mexican peso. The actions come as the U.S. tries to strike a revised North American Free Trade Agreement deal with Canada and Mexico, and settle other trade concerns with the EU. It will increase tensions with allies even as the U.S. seeks help to address alleged trade abuses by China. The Commerce secretary said the exemptions would end in part because NAFTA talks are "taking longer than we had hoped." Negotiations with Europe have "made some progress" but not gone far enough to warrant more relief from the tariffs, he added. "We look forward to continued negotiations both with Canada and Mexico on the one hand, and with the European Commission on the other hand, because there are other issues that we also need to get resolved," Ross said.