Confirm every important point in writing, even after a phone or video call, so there is a record both sides can refer back to. Time zone differences mean a same-day reply is not always realistic; build this into your planning rather than treating slow responses as automatically suspicious.
Suppliers who deal successfully with international buyers over years tend to value the relationship, not just the single transaction, because repeat buyers are more profitable than one-off ones. Treating a good supplier well, paying on time, and being clear and professional in your communication is itself a form of risk management: it is how you become a customer a supplier does not want to lose.