Set up your bank account for direct deposit/EFT (electronic funds transfer), and all earnings from foreign sales will be deposited into your account in US dollars.
There's no reason to avoid foreign sales. This month Canada and Australia are doing better than the US market for me. And their Canadian and Australian dollars will have been converted by the time they reach my account.
But if for some reason you don't want to sell elsewhere, don't check Worldwide on the last page of the metadata, where it asks where you want the book distributed. Choose just US.
Jack Encell wrote:
If Amazon doesn't convert foreign currency to USD, I don't want to sell in other countries. How do I go about making it available ONLY in USA.
Your bank converts the monies to USD and applies the fx rate in effect on the day it's credited; the amount is then reported to KDP and posted on your payments table. Choose "Worldwide" for your markets. It doesn't make sense not to.