Service deployment in multicluster environment on Azure

Below is what I am looking for.

For our production setup we would like to deploy our application say App1 to multiple clusters across different regions. App1 is an backend micro service component. Lets say when request from another app within a given cluster is made to App1 we want istio to to the job of traffic manager to understand if the App1 in local cluster is up and running or not and if not call the service within another cluster based on some algorithm e.g. geolocation based.

I do not find any specific document which talks about this or even mentions if it is possible.

Can you please help us understand if this possible or not. As an alternate approach we were thinking about is to use traffic manager on top of the AKS clusters and have the traffic manager URL within calling application who wants to talk to App1 so that it can route to an available app1 irrespective whether it is in local region or within different region/cluster