WASHINGTON (AFP) - The United States Commerce Department announced on Tuesday (Aug 8) that it was imposing preliminary duties ranging from 16.5-81 per cent on aluminium foil imports from China after finding they were subsidised.

The department "will instruct US Customs and Border Protection to collect cash deposits from importers of aluminium foil from China based on these preliminary rates", it quoted Commerce Secretary Wilbur Ross saying in a statement.

Aluminium imports from China were valued at an estimated US$389 million (S$530 million) in 2016, according to official figures.

The move follows an anti-dumping investigation announced in spring, with a final decision to be made on Oct 24.

"The United States is committed to free, fair and reciprocal trade, and will continue to validate the information provided to us that brought us to this decision," said Secretary Ross. "The Trump Administration will not stand idly by as harmful trade practices from foreign nations attempt to take advantage of our essential industries, workers, and businesses."

The investigation is separate from another probe, launched in April, that is looking at whether aluminium dumping and illegal subsidies are threatening the US economy and military preparedness.

Along with steel, aluminium is an essential material for the US military.

US manufacturers had demanded the imposition of tariffs on Chinese imports, arguing that government subsidies were responsible for a global excess in supply.

President Donald Trump promised during his election campaign that the US would tighten its trade policy towards China, in order to bring back manufacturing jobs.

But he had so far avoided major moves in this regard since taking office, favouring a softer approach to gain Chinese cooperation in reining back a recalcitrant North Korea.