U.S. President Donald Trump signed an executive order on Tuesday doubling the country’s tariffs on steel and aluminum imports to 50 percent.
 
The White House published the order online after press secretary Karoline Leavitt announced the decision in a briefing.

The new tariffs went into effect at 12:01 a.m. Eastern Time Wednesday, or 1:01 p.m. in South Korea. 

Trump had earlier disclosed plans to raise the tariffs at a rally in Pennsylvania on Friday, and in a social media post shortly after that he said the new tariffs will take effect Wednesday. 

The increased tariffs are expected to deal a blow to the South Korean steel industry, with exports to the U.S. accounting for about 13 percent of the nation’s total steel shipments last year.

Experts said the new tariffs will also place a significant burden on the U.S. economy as prices of steel and aluminum products, which are mostly imported, will inevitably go up.