Adding credit card to US region apple store

I am currently living and using my iphone in Bangladesh which has no official apple store. Therefore i have been using my Locally issued American Express credit card that was linked with my id for a long time to make purchases from app store. However, the card had expired and i tried to add the new card issued by the bank but unfortunately it is not being accept and keeps getting declined constantly. I tried adding some other credit cards such as VISA and Mastercard but still no luck. How am i supposed to add my international credit card to the payment method?

Thanks in advance