You should be able to do that with our new automation app, Mr. Arigato. If you install the app, reach out using our request help feature and I can help you get it going.
Once successful, we'll post an anonymized version to our public library for other merchants to use as a starting point.
This is Reuben, from Autofulfill Team. This requirement can be done by Autofulfill App.
The app has a filter option which will filter the orders based on the shipping country. Auto Fulfill can send the orders to the USA suppliers separately and to the Asian suppliers separately by filtering the orders on Shipping country.