The UN’s postal agency has voted unanimously to reform its fees, potentially averting a US withdrawal.
The compromise deal was agreed after two days of emergency talks by the Universal Postal Union (UPU) in Geneva.
The agreement means the US and other high volume importers can set their own rates for delivering mail from abroad.
The US had earlier threatened to pull out, arguing that discount rates for countries such as China were putting the US at a massive disadvantage.
It said that it had become cheaper for US consumers to ship items from China rather than buying domestically. As a result, it argued this was unfair to US manufacturers and was costing the US Postal Service up to $500m ($404m) a year.
The UPU is a 145-year-old agency that sets the prices of international mail, with the mandate of ensuring that global postage is affordable to all.
Its 193 members are categorised into different postal rates based on their economic and postal development.
UPU Director-General Bishar Hussein called the new agreement an “historical moment”, but conceded that higher rates would mean more costs for some people.
From January 2021, high-volume importers will be able to impose “self-declared rates” for delivering foreign mail and packages.
Countries that import more than 75,000 tonnes (75m kgs) of post every year can apply their own rates by July 2020.
A five-year period for phasing in new fees has also been agreed upon to help with the transition.