If the US has kinetic weapons in space, I very much doubt they would plan to use them against North Korea. NK is decades behind in military technology, and the US/SK forces would have air supremacy over NK in a matter of hours, with the capability to pummel anywhere in the country with conventional weapons with relative impunity.
If they have them, using them would almost certainly tip their hand to Russia / China etc, and lose them a significant strategic advantage in any future conflict. Trump and his cronies have been talking tough about China (Bannon literally said 'We're going to war in the South China Sea ... no doubt') and while it is a) doubtful that this will happen, given the recent warming of relations with China (mmmm... chocolate cake) and b) in the event it does happen, unlikely to escalate to the use of previously undisclosed super-weapons, it still makes sense to keep this hypothetical weapon secret from larger, more-powerful potential adversaries, just in case.
Also, if they're rearming with Kinetic Weapons it suggests they've already fired a few
> Power supply for electronic warfare sources?
Since you mention a power supply, I'm going to assume you don't mean dropping EMP bombs, which, even if they exist would be more easily dropped from high altitude aircraft, and would likely be less effective against such an outdated military.
I'm going to assume instead you mean some kind of cyber-weapon. The alleged cyberwarfare campaign against NK's ICBM programme most likely takes the form of malware (like stuxnet) introduced through conventional hacking methods or even on-site deployment. Sure, you can send someone a phishing email from space, but it's not any more effective than sending it from an office somewhere.
