Why in heaven’s name would Russia ask North Korea for help. This is a photo that North Korea released to show their troops’ readiness.
Notice that guy kneeling? He’s got a pistol instead of an automatic rifle. If they can’t give everyone a rifle then how can they help Russia?
Plus there’s the logistics of getting them across all of China and Russia.
———- UPDATE ———-
First of all, thank you for all the up votes.
Second, people have pointed out that Korea and Russia do share a border. It’s a very tiny bit on the north east tip and doesn’t show up on most maps. So they could take troops without crossing China. And their air force is just as impressive as their troops.