Well, there might have been a few working Chinese prototypes, but they would likely be inferior to the US ones.

The Chinese had Power Armor and probrably developed their own distinct version, although they probrably had less troops in PA. It would't surprise me if the european big boys (France, United Kingdown, Germany, Soviet Union) had Power Armor and used it during the Resource Wars. Afterall, the Germans aparently developed the gauss rifle, or at least the M72, that is.