Hi Vincenzo,
At present, SAP HCP accounts (in which apps run) "live" either in the EU or US data center. You can of course deploy the same app in both landscapes but they will be two independent apps (separate URLs, data, etc.)
Yet, as you can imagine your use case is quite common and natural, it's already addressed and solution is being designed. Stay tuned! 
Cheers,
--Vlado