Songnam
From Halopedia, the Halo wiki
Summary
The Spartan'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.