US President Donald Trump said Monday that gold imports will not face additional tariffs, days after confusion flared on whether recent hikes applied to certain gold bars — threatening to upend global trade of the precious metal.

Trump's comments came after US customs authorities made public a letter saying that gold bars at two standard weights — one kilogram and 100 ounces (2.8 kilos) -- should be classified as subject to duties.

"Gold will not be Tariffed!" Trump said on his Truth Social platform, without providing further details.

The letter, which was made public last week and dated 31 July, was first reported on by the Financial Times, sending the price of gold on the US futures market to a record high.

But a White House official told AFP on Friday that the Trump administration plans to "issue an executive order in the near future clarifying misinformation about the tariffing of gold bars and other specialty products."

On Friday, gold for December delivery hit a record high on the Comex, the world's biggest futures market.

The concern is whether gold products would be exempt from Trump's "reciprocal" tariffs impacting goods from dozens of economies including Switzerland, which sees a 39-percent levy.

One-kilo bars are the most common form traded on Comex and comprise the bulk of Switzerland's bullion exports to the US, the FT said.

The US customs ruling letter, typically used to clarify trade policy, came as a shock amid expectations that gold bars would be classified under a different customs code that spared them from Trump's countrywide levies.

Gold, seen as a safe haven investment, already reached record highs this year on tariff worries and geopolitical unrest.