Let's not forget the close ties NK has with China. Sphere of influence can be seen as just as important to China as it is to any western nation, and the chance of Cinese participation in any exchange is entirely possible.
That being said, NK is playing a dangerous game. Yes, the US does inform other nations before a missile test is conducted. It is also very well advertised through other sources. I told every one here on Saturday of the scheduled firing.
http://www.subsim.com/radioroom/showthread.php?t=153195
This one hour notification by NK could lead to trouble. I know part of it is meant to measure US response to short notice events, but it could go tragically wrong.