President Donald Trump unveiled fresh tariffs on China last weekend, including an additional 10 percent levy on goods that came into force on Tuesday.

That measure also suspended an exemption allowing imports valued at $800 or below to enter the United States duty-free -- after the provision came under heavy scrutiny.

US officials have pointed to the growth of Chinese-founded online retailers Shein and Temu as a key factor behind a surge in shipments involving the "de minimis" exemption.

But Tuesday's suspension threatened major delays to parcels from both companies entering the country.

On Friday, a White House order updating the earlier rule said duty-free treatment can continue until the US commerce secretary deemed that "adequate systems are in place to fully and expediently process and collect tariff revenue."

Shipments claiming the "de minimis" exemption climbed from some 139 million annually in fiscal year 2015 to more than one billion annually in fiscal year 2023, according to US Customs and Border Protection data.

The closing of the trade loophole could disrupt the business models of e-commerce giants Shein and Temu, with consumers potentially bearing the brunt of costs, analysts have said.

Both platforms boast a massive selection of ultra-cheap products at a time when inflation has shrunk household spending power almost everywhere.