Is it really this info ? If yes when we can travel from Russia to North Koreea via Usurjisk-Khasan ?
Well, in many cases it is not the best thing to trust the source from where you took this info or at least there is always a need to recheck it
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In this very case it is wrong because:
1) Pyongyang carriages via China are still running and you can purchase tickets for those, they are still in timetable (till 10/12, last departure dare before timetable change) etc.
2) No info whatsoever about such thing in Russian speaking internet or RZD/MZA websites. RZD/MZA and Russian speaking forums would be exactly the place to search for such things, but your "source", as far as we know, doesn't even speak Russian to check it
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3) Huge changes like this usually not happen in the middle of the season.
Another inaccuracy is that Khasan-Tumangan crossing is closed for foreigners. It is not true, we know at least couple cases of successful border crossing there by non Russian/Korean citizens, exactly Moscow- Pyongyang carriage was used.