The U.S. Mint uses a network of Authorized Purchasers for its bullion coins. Many of these same distributors, such as APMEX , SD Bullion , and U.S. Gold Bureau , also sell gold bars from private and other sovereign mints.
Since you cannot buy them directly from the U.S. Mint, you can source high-quality gold bars through several reputable channels: how to buy gold bars from us mint
Well-known names include PAMP Suisse , Valcambi , and Sunshine Minting . These bars often come with assay cards to verify weight and purity. such as APMEX
If you specifically want a gold product issued and guaranteed by the U.S. government, you can purchase bullion or collectible coins: Bullion Coins - U.S. Mint and U.S. Gold Bureau