It almost certainly is both. The only other things they do (and they can combine trips/objectives) is spy on US and Japanese military installations in Japan, shuttle spies/currency back and forth, kidnap Japanese citizens to make them Japanese language teachers/spies in Pyongyang, and map out further information on Japanese nuclear power plants).
All of these missions made clear by the testimony of defecting DPRK agents/military.
SLEEP WITH DA FISHES......