The US Commerce Department has announced plans to impose tariffs of up to 3,521% on imports of solar panels from four South East Asian countries. It comes after an investigation that began a year ago when several major solar equipment producers asked the administration of then-President Joe Biden to protect their US operations.

The U.S. announced tariffs on Malaysia, Cambodia, Vietnam, and Thailand on Monday, capping a yearlong trade probe initiated under the Biden administration.

US trade officials finalized steep tariff levels on most solar cells from Southeast Asia, a key step toward wrapping up a year-old trade case in which American manufacturers accused Chinese companies of flooding the market with unfairly cheap goods.