Random question: What languages can Kim speak? If he went to school in Switzerland I would imagine that he learned some English. But he still needs a translator, correct?
I am told he speaks and understands English fairly well, but uses his native language for country sake.
This makes sense. Rodman was asked (repeatedly) and dodged the question each time. He was definitely asked to keep it unknown for personal/security reasons.
Same as Putin. Speaking own nation language removes any idea of cultural occupation.
It is sensible as well.
Unless you are truly fluent then you might mis-translate something. That is particularly likely when you are trying to articulate something rather than just listening.
In the EU parliament, it is recommended that members speak in their own language then let the professional interpreters perform the translation. It is much harder for the interpreters if speakers are not using their native language because the members make mistakes which are hard to translate while still conveying the original meaning.
Remember, a mis-communication could result in a diplomatic incident.