Songnam
From Halopedia, the Halo wiki
Songnam is a city located on the Korean Peninsula of planet Earth. In 2552, SPARTAN-117's new MJOLNIR Mark VI armor was shipped to Cairo Station from Songnam, Korea. Is it is a possibility that the new armor was constructed there, due to the fall of the ONI facilities on Reach. It would make sense, as well, due to the fact that there is currently a US military base in real-life Songnam. However, the Mark VI's construction there hasn't been confirmed by Bungie yet. The Armory's Master Gunnery Sergeant tells SPARTAN-117 that the armor came from Songnam with excellent timing: Only the morning before the First Battle of Earth.
In the Halo Graphic Novel, SPARTAN-062 tests the Mark VI's armor against a squad of ODSTs.