The Universal Postal Union (UPU) announced Saturday that 88 countries have either fully or partially suspended postal services with the United States, after volumes dropped by more than 80% due to Washington’s imposition of additional customs tariffs.

UPU Director General Masahiko Metoki said in a statement that the organization is working on a rapid technical solution to allow the resumption of mail deliveries to the U.S., according to AFP.

The disruption has raised concerns over its impact on e-commerce, postal remittances, and personal correspondence, given that the United States is one of the main hubs for global mail traffic.