One kilo gold bars are pictured at the plant of gold and silver refiner and bar manufacturer Argor-Heraeus in Mendrisio, Switzerland, July 13, 2022. REUTERS/Denis Balibouse/File Photo

WASHINGTON (Reuters) -The United States has imposed tariffs on imports of one-kilo gold bars, the Financial Times reported on Thursday, citing a letter from Customs Border Protection.

The letter - dated July 31 - said one-kilo and 100 ounce gold bars should be classified under a customs code subject to levels, according to the newspaper, which added that the move could impact Switzerland, the world's largest refining hub.

(Reporting by Jasper Ward)