Hongkong Post announced on Wednesday an immediate suspension of parcel services to the United States via surface mail, due to the longer shipping time as small parcels are due to be hit by US tariffs from May 2.
It said it would contact the senders of such mail to make return and refund arrangements from April 22 if their parcels had not yet been shipped to the US.
For air parcels, services will stop from April 27.
"The US is unreasonable, bullying and imposing tariffs abusively. Hongkong Post will definitely not collect any so-called tariffs on behalf of the US and will suspend the acceptance of postal items containing goods destined to the US," a statement said.
Other postal items containing documents only without goods will not be affected.