At least 25 countries have decided to suspend package deliveries to the United States, as concern grows over the impact of U.S. President Donald Trump’s looming tariffs, a UN body said Tuesday.

The Trump administration said late last month that it will abolish a tax exemption on small packages entering the United States from August 29.

The move has sparked a flurry of announcements from postal services, including in France, Britain, Germany, Italy, India, Australia and Japan, that most U.S.-bound packages would no longer be accepted.

The United Nations’ Universal Postal Union said it had already been advised by 25 member countries that their postal operators “have suspended their outbound postal services to the U.S., citing uncertainties specifically related to transit services”.

It said the suspensions will remain in place until there is more clarity on how U.S. authorities plan to implement the announced measures.

The UPU did not provide a list of postal services it had heard from.