It's "very likely" that the proposed steel and aluminum tariffs announced by President Donald Trump on Thursday will be signed into law next week, said steel analyst Matthew Miller.
"Down the road we can possibly see ramifications of other countries trying to implement their own tariffs," Miller, of CFRA Research, told CNBC on "Power Lunch."
Earlier this month, the Commerce Department recommended imposing the measures, and Thursday the president followed through — saying the U.S. will set tariffs of 25 percent for steel and 10 percent for aluminum to be broadly implemented without targeting specific countries and without quotas.
Steel stocks rallied strongly after the news Thursday afternoon. But the broader market tanked, with the Dow Jones industrial average falling more than 550 points at one stage on concerns about a trade war erupting. The Dow had been up more than 150 points earlier in the session.
Meanwhile, fears of a possible trade war abounded even before Thursday's announcement. Charles Bobrinskoy, vice chairman and head of investment group for Ariel Investments, told CNBC on Monday that the Great Depression began over trade wars.
It's unclear if the tariffs would apply to all imports or only certain metals, Miller said Thursday, but added that the construction and automotive industries will be hit the hardest.
"Ultimately, [valuations are] positive for steel and aluminum today," he said. "We have to wait to see what it means for the GOP political landscape moving forward."