GENEVA, Aug. 26 (Xinhua) -- The Universal Postal Union (UPU) announced on Tuesday that 25 member countries have suspended postal shipments to the United States, citing uncertainties linked to planned changes by the U.S. administration to its rules on customs clearance of imports valued less than 800 U.S. dollars.

As the United Nations specialized agency for the postal sector with 192 member countries, the UPU said in a statement that it is working with U.S. authorities to ensure that details of the new operational requirements are clearly communicated to its members.

The statement also noted that the UPU Director General Masahiko Metoki also conveyed member states' concerns about potential disruptions in a letter to U.S. Secretary of State Marco Rubio on Monday.

According to an executive order signed by U.S. President Donald Trump, the long-standing "de minimis" exemption rule, which allowed goods worth less 800 U.S. dollars to enter duty-free, is to end Aug. 29.

The UPU said it is taking all possible measures to prepare its member countries for the impacts of the new requirements. ■