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 proposed levies – targeting companies in Cambodia, Thailand, Malaysia and Vietnam – are in response to allegations of subsidies from China and the dumping of unfairly cheap products in the US market.
A separate US government agency, the International Trade Commission, is due to reach a final decision on the new tariffs in June.
The countervailing and anti-dumping duties, as these tariffs are known, vary between companies and the countries their products are made in.
Some solar equipment exporters in Cambodia face the highest duties of 3,521% because of what was seen as a lack of cooperation with the Commerce Department investigation.
Products made in Malaysia by Chinese manufacturer Jinko Solar faced some of the lowest duties of just over 41%.
Another China-based firm, Trina Solar, faces tariffs of 375% for the products it makes in Thailand.
Neither company immediately responded to requests for comment from BBC News.
