- Other tariff targets could be "very critical industries that guide our economy, that make sure we have a strong national security," says Dan DiMicco.
- On Thursday, Trump announced tariffs on steel and aluminum starting as early as next week.
- DiMicco called the tariffs "completely justified."
The tariffs announced by President Donald Trump on Thursday most likely won't be the last from the administration, according to former Trump trade advisor Dan DiMicco.
The United States will impose a 25 percent tariff for steel and a 10 percent tariff for aluminum as early as next week.
"Trump is just getting started when it comes to trade," said DiMicco, former CEO of steel producer Nucor.
Other targets could be "very critical industries that guide our economy, that make sure we have a strong national security," he said in an interview with "Power Lunch" on Thursday.
DiMicco called the tariffs "completely justified."
"What we're doing with this is stopping the trade cheating, where they've been breaking the global trade laws," he said.
"The hard reality for most domestic manufacturers, including the steel industry, is that we've been in a trade war with China for 20 years. And now is the first time that we are standing up and saying, 'Enough's enough, we're going to fight back.'"
In the announcement Thursday, Trump claimed trade trends "destroyed" American steel and aluminum industries.
"People have no idea how badly our country has been treated by other countries," the president said.
Trump's actions sparked fears of a trade war, as well as higher prices for consumers.
DiMicco says investors are missing the point, calling the market drop a "major overreaction."
"What the market needs to focus on is the long-term impacts of his total economic plan, which does include trade reform and rightfully so," he argued.
That plan also includes tax, regulatory and energy reform, as well as some infrastructure spending, he said.
"It's a great buying opportunity," he said. "Costs of steel are a small portion of most of the products that people are afraid about influencing."
— CNBC's Jacob Pramuk contributed to this report.