The Commerce Department's recommendations followed investigations that deemed the imports to be a threat to national security. If adopted, the measures would mark another trade remedy undertaken by the Trump administration after it slapped tariffs on washing machines and solar cell panels imported from South Korean and other manufacturers.

"Recently, we put a tariff on washing machines because we were getting killed, believe it or not, on washing machines and solar panels," Trump said. "That was two months ago. You have to see the activity on new plants being built for washing machines, and for solar panels."

He claimed there were 32 solar panel plants in the US that were "dead" -- 30 were closed while two were on "life-to-life resuscitation."

"Now, they're talking about opening up many of them, reopening plants that have been closed for a long time," Trump said. "And we make better solar panels than China."

On steel, the Commerce Department recommended three alternatives -- a global tariff of at least 24 percent on all steel imports from all countries, a tariff of at least 53 percent on all steel imports from 12 countries, including South Korea, with a quota on imports from all other countries, or a quota for all countries equal to 63 percent of their respective 2017 exports to the US.

Trump is required to make a decision by April 11. (Yonhap)