The United States Postal Service announced Tuesday night that it is temporarily suspending accepting packages sent from China and Hong Kong until further notice. The suspension is effective immediately, the USPS said. Letters and flats are not included in the suspension, it said.

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.