The U.S. Commerce Department said on Tuesday it would impose duties of up to 456% on certain steel produced in South Korea or Taiwan that are then shipped to Vietnam for minor processing and finally exported to the United States.

The agency said in a statement that it had found corrosion-resistant steel products and cold-rolled steel produced in Vietnam using substrate of South Korean or Taiwanese origin had circumvented U.S. anti-dumping and anti-subsidy duties.

The duties on South Korean and Taiwanese products were imposed in December 2015 and February 2016. Since those dates through April 2019, shipments of corrosion-resistant steel products and cold-rolled steel from Vietnam to the United States had increased by 332 percent and 916 percent compared with similar periods immediately before, the statement said.

It said the Commerce Department inquiry was initiated at the request of ArcelorMittal SA's U.S. unit, Nucor Corp , United States Steel Corp, Steel Dynamics Inc , California Steel Industries, and AK Steel Corp.