That link supports Tefal's statement (not that I know for sure it is correct, but the link just posted doesn't contradict it)
It would be more accurate to say that the USA rounded up people based on Ethnicity. (Japanese Americans) Many of these people were full USA citizens, not enemy Aliens as in the UK.
The US shouldn't beat themselves up about this however, as an initial response to Pearl the reaction was not a totally unreasonable one.
The US authorities were concerned that the, very strong, traditional Japanese culture of "Nationality by Blood" and family ties might well mean that even Full Japanese American citizens might present a risk of supporting the home islands in the War.