Only parcels arriving in the US from China and Hong Kong are affected for now, as the restriction doesn't apply to letters and flat mail.

As part of new tariffs on Chinese imports, President Donald Trump eliminated an exemption for small packages, vastly increasing the amount of parcels US Customs and Border Protection needs to inspect.

The U.S. Postal Service’s decision may block or delay parcels from retailers including Shein and Temu from entering the United States.