The Biden administration is taking the first step toward a review of tariffs on more than US$300 billion (HK$2.34 trillion) in Chinese imports that is required to keep them from starting to automatically expire in July.

The US Trade Representative's office is notifying domestic industries that benefit from the duties of their possible end on their fourth anniversary, and the opportunity to request that they remain, it said.

If a request for continuation is received by July 6, the office will keep the tariffs in place as it conducts a review to determine their need going forward, officials told reporters at a briefing.

A review would include an opportunity for all interested persons to provide comments.

The office is sending notice of the expiration to about 600 stakeholders, according to the officials.

The evaluation is officially known as a "review of necessity," which relates to Section 301 of the Trade Act of 1974.

President Donald Trump used that law to hit China with the tariffs ranging from footwear and clothing to electronics and bicycles and even pet food starting in July 2018 after an investigation that concluded China stole intellectual property from American companies and forced them to transfer technology.