Trump, 78, argued that the so-called de minimus exception allowed shippers from the People’s Republic and Hong Kong to “hide illicit substances” in packaging and products.

The move appears to be a massive blow to fast-fashion companies such as China-based Shein and Temu, which managed to rapidly expand in the US through the almost century-old de minimis rule. This tariff exemption will end on 2 May, the White House said on Wednesday.

Trump increased the blanket tariff on Chinese imports to 54 percent and imposed new duties on major trading partners including Japan, South Korea and Taiwan.