WASHINGTON (Reuters) - The U.S. Trade Representative's office said on Thursday it will accept public comments starting on Monday on its plans for steep tariff increases on Chinese polysilicon, silicon wafers and tungsten products.

The tariff increases were added to the Biden administration's final determination on "Section 301" tariffs on Chinese electric vehicles, batteries, steel, semiconductors and solar cells announced last week.

After reviewing public comments on those tariff hikes, many of which are due to start on Sept. 27, including the 100% duty on Chinese EVs, USTR said it would add five product categories. These include 50% duties on polysilicon used in solar cells and silicon wafers used in semiconductors and 25% duties on three categories of processed tungsten, including unwrought and bars, plates, rods, sheets and foil.

In a Federal Register notice, USTR said the docket for public comments will open on Monday and close on Oct. 22.

(Reporting by David Lawder; Editing by Cynthia Osterman)