Without that approval the best you're looking at (from his perspective) is mass unrest which an opportunistic nation like their neighbor could foment, support, and exploit.
Oh and has send thousands of its citizens to die in Ukraine.
We require more minerals…
When the USSR collapsed in the 90s, they no longer had any source for oil owing to sanctions. Their farming was thus severely impaired, and starvation was the predictable result.
We then post facto gave them emergency aid, likely with the idea of turning the people against their government and to the people starving them for geopolitics. Shockingly, it didn't work.
Their deepening relationship with Russia is mostly just a return to the past.
I think this is yet another example of how sanctions are quite a useless tool. If we'd straight up gone for the carrot (perhaps simply trading oil for arms at fair market rates) instead of waiting to starve people first, North Korea could very possibly be a friendly nation today.
Of course this sounds absurd only because most people don't realize South Korea was also under brutal dictatorships for most of its life since the Korean War (their first democratic election was in 1987) - big difference is those dictatorships were backed by the West and allowed to engage in more normal trade and development.
Realpolitik is far dirtier (and often painfully myopic) than most realize. I'd love to read a textbook about current times from a few hundred years from now...
1. Cut communications;
2. Make sure the troops you send to capture critical objectives are hardcore loyalists (or at least paid exceedingly well).