DHL, which owns the Deutsche Post service, said that from Saturday it would “temporarily suspend” its standard category of package delivery to the US, the preferred option for many small businesses.

“The reason for the restrictions, which we expect to be temporary, is new processes for postal delivery which have been put in place by the US authorities,” DHL said in a statement.

“Important questions have not yet been answered, including who will have to pay the tariffs and how,” it added.

Other European postal services, for example in Belgium, Austria and Denmark, have already taken similar measures.

DHL said a more expensive “express” service for packages weighing up to 70kg will still be available.

Individual customers will also still be able to send items as presents with a maximum value of US$100 (€86) but DHL warned that these would be subject to extra checks to prevent the service from being used for commercial goods.

In late July the Trump administration said that as of Aug 29 it would abolish a tax exemption on small packages entering the US.

Such packages with a worth of less than 800 euros will now be taxed at 15%, the same rate as other imports from the EU.

That general tariff rate was agreed under a deal struck between Brussels and Washington late last month.

In April DHL announced it was suspending delivery of packages to the US with a value in excess of €800.