word order - When stating a non-Japanese name, should the surname come first?

When stating a full non-Japanese name, should one use the "Surname Firstname" rule used for Japanese names (i.e. "Smith John / スミス ジョン") or the name's native rule (in the case of an English name, "Firstname Surname" (i.e. "John Smith / ジョン スミス")).

Which format would native Japanese speakers use, when stating an obviously non-Japanese full name?

Answer

Typically, you state it in the order that is normal for your language. Koreans and Chinese say their family name first, Americans say it last. Japanese people are well aware of that language difference, so they expect us to keep our names in the original order. They also use the original order when saying foreign names themselves.

The only times I put my last name first is when I'm required to do so, as in opening a bank account.