This is an older article from CNN but worth reading for a better understanding of the geopolitical nature of the Korean peninsula right now.  Russia is trying to be an ascendant power on the global stage and recapture the superpower status that the USSR enjoyed.  If they are in agreement with China that the largest threat to stability in the region is President Trump, they will now be able to work together.  Russia will gain influence over a former country that it had a dominant relationship with, and perhaps strengthen its hold on disputed Japanese islands it has claimed since the end of World War II (REMINDER: No peace treaty was ever signed between Japan and Russia resolving their conflict at the end of the World War II).

http://www.msn.com/en-us/news/world/russias-north-korea-power-play-unsettles-china-and-us/ar-AAr50tI?ocid=spartandhp