Presumably each training speech sample is labelled with native language. For Portuguese there would be two distinct clusters: Portugal and Brazil. If your speech is in either cluster, it would just tell you that your native language is Portuguese without being any more specific. Sure, it's a missed opportunity but it doesn't distinguish Jamaicans from Australians either.

I presume there's enough difference between English spoken by Portuguese and English spoken by Russians for those also to be distinct clusters.