President Donald Trump is preparing to announce steel and aluminum tariffs on Thursday.

“Our Steel and Aluminum industries (and many others) have been decimated by decades of unfair trade and bad policy with countries from around the world,” Trump wrote on Twitter.

Bloomberg’s Jennifer Jacobs revealed that Trump may increase tariffs by as much as 25 percent on steel and 10 percent on aluminium.

Scoop: Trump is set to announce steep tariffs on steel and aluminum imports Thursday — and he has told aides he wants 25 percent on steel and 10 percent on aluminum, sources tell me, @JoeDeaux and @andrewmayeda. — Jennifer Jacobs (@JenniferJJacobs) March 1, 2018

The president has long sought tough trade actions and tariffs in his administration, but the contentious issue remains elusive.

“We must not let our country, companies and workers be taken advantage of any longer,” he said. “We want free, fair and SMART TRADE!”

Our Steel and Aluminum industries (and many others) have been decimated by decades of unfair trade and bad policy with countries from around the world. We must not let our country, companies and workers be taken advantage of any longer. We want free, fair and SMART TRADE! — Donald J. Trump (@realDonaldTrump) March 1, 2018

The move would be a significant challenge to China, which continues to flood the U.S. market with cheap steel and aluminum.

In February, the Commerce Department led by Wilbur Ross, concluded a study that said the imports threatened national security.

Trump met with concerned members of Congress on February 13, saying that he appreciated the need for cheap steel for manufacturing, but felt that the steel industry in the United States was “decimated” by sustained cheap foreign imports.

“You have countries that are so overproducing, and what they’re doing is they are dumping it on us,” he said. “And you look at empty factories, steel factories, and plants, and it’s a very sad thing to look at.”