The US Postal Service (USPS) says it has stopped accepting parcels from mainland China and Hong Kong until further notice.
Letters will not be affected by the suspension, according to a statement on the company’s website.
USPS did not offer a reason for the decision but it comes after US President Donald Trump imposed an additional 10% tariff on all goods imported to the US from China.
Trump’s executive order also eliminated an exemption that allowed goods worth $800 (£641) or less to enter the US without having to pay duties or certain taxes.
The so-called de minimis tax loophole faced increased scrutiny in recent years as Chinese e-commerce giants like Shein and Temu used it to reach millions of US customers.
In response China said it would implement tariffs on some US imports.
From 10 February coal and liquefied natural gas products (LNG) will face a 15% levy. Crude oil, agricultural machinery and large-engine cars will be subject to a 10% tariff.
President Trump is expected to speak to his Chinese counterpart Xi Jinping in the coming days.
“Trump’s tariff changes are especially sharp if goods were previously shipped via e-commerce directly from China to the US,” said trade expert Deborah Elms.
Close to half of all parcels entering the US under de minimis were sent from China, according to a 2023 report by the US Congressional committee on China.
US officials have pointed out that the large flow of parcels entering the country through this exemption made it increasingly difficult to screen them for possible illegal goods.
The BBC has contacted USPS to request more details about the decision.
