China said on Monday it "resolutely opposed" to a US investigation into its semiconductor industry, calling it "protectionist".
"The US 301 investigation has obvious unilateral and protectionist tones," the Commerce Ministry said in a statement, calling on Washington to immediately stop its "wrong practices".
The Biden administration announced a last-minute trade investigation into older Chinese-made "legacy" semiconductors that could heap more US tariffs on chips from China that power everyday goods from cars to washing machines to telecoms gear.
US Trade Representative Katherine Tai said the probe aimed to protect American and other semiconductor producers from China's domestic chip supply.
The "Section 301" probe, launched four weeks before President-elect Donald Trump takes office on January 20, will be handed over to his administration in January for completion, Biden administration officials said.
The effort could offer Trump a ready avenue to begin imposing some of the hefty 60 percent tariffs he has threatened on Chinese imports.
Departing President Joe Biden has already imposed a 50 percent US tariff on Chinese semiconductors that starts on January 1. His administration also has tightened export curbs on advanced artificial intelligence and memory chips and chipmaking equipment.
Legacy chips use older manufacturing processes introduced more than a decade ago and are often far simpler than chips used in AI applications or sophisticated microprocessors.
US Commerce Secretary Gina Raimondo said on Monday her department's research showed that two-thirds of US products using chips had Chinese legacy chips in them, and half of US companies did not know the origin of their chips, including some in the defence industry, findings that were "fairly alarming."
The Commerce Ministry said in a statement that the US chips probe would hurt American firms and disrupt the global chip supply chain. It said Beijing would "take all necessary measures to firmly defend its rights and interests." (Agencies)