STOCKHOLM (Reuters) -Norwegian and Swedish-Danish postal groups Posten Bring and PostNord are pausing parcel shipments to the United States ahead of the scrapping of a U.S. customs tax loophole that allows duty-free entry for low-value packages, they said on Wednesday.

U.S. President Donald Trump's administration said last month it would suspend the global "de minimis" exemption, which also allows minimal paperwork, for international shipments under $800 effective August 29.

"Due to the short timeframe to adapt to the new requirements, PostNord is temporarily halting shipments," the company owned by the Swedish and Danish governments said in a statement.

The twists and turns in Trump's tariff policies have roiled global financial markets.

Under the executive order suspending the "de minimis" exemption, low-value packages sent to the U.S. will face "all applicable duties", according to the White House.

"The details surrounding this have not yet been clarified by the U.S. customs authorities, and no system solutions have been developed that postal companies can use," Norway's state-owned Posten Bring said in a separate statement.

It said postal companies in Europe were working together to gain clarity.