Trump made the amendment in an executive order that went public on Thursday Hong Kong time.
Tariffs on parcels will go up from US$75 to US$100 from May 2 and from US$150 to US$200 from June 1.
The jump in tariffs closes a trade exemption rule known de minimis that has allowed low-value packages from mainland China, Hong Kong and Macau to enter the United States free of duties.
It means people wanting to send small parcels worth up to US$800, which are currently exempt from any duties, to the US from the mainland, Hong Kong or Macau will now have to pay US$100 per item posted between May 2 and before June 1 and US$200 for goods sent after June 1.
The skyrocketing increase in duties comes as the number of shipments entering the US through the duty-free route has exploded in recent years, reaching nearly 1.4 billion packages last year.
More than 90 percent of these packages now enter under the de minimis rule, and of those, about 60 percent come from China, led by direct-to-consumer retailers such as Temu and Shein.
The jump in duties on small goods parcels has been framed by Trump as a solution to the national emergency arising from the US trade deficits and in his starting a tit-for-tat trade war that has seen him levy a punitive 145 percent tariff on Chinese imports.
China has said no one wins in a trade war and described the tariffs as protectionist.
