The duties will apply to all shipments that have entered the US since November 4, 2016, the date the circumvention petitions were initiated.

US Customs & Border Protection will collect anti-dumping duties of 199.43% and countervailing duties of 39.05% on coated material, with the corresponding levies on cold-rolled material at 265.79% and 256.44% respectively - the same duties as are applied to Chinese product.

Importers of cold-rolled and coated products made from Vietnamese steel, or that from third-party countries, can seek an exemption from potentially massive cash deposits if they can certify that the substrate did not come from China, Commerce said.

The agency plans to announce its final determination on February 16, 2018.

Preliminary decisions in the Vietnam circumvention cases have been subject to multiple delays. Commerce last month cited their complexity, which could result in a precedent-setting change to the definition of “substantial transformation” that is used in the determination.