I haven't tested it to be absolutely sure, but you should be able to stop the move by simply changing states. Do you have an appropriate event on that node where you are doing the moving? If you don't the move will happen until it's done, then the state will change to whatever one is actually listening for other events. If that doesn't make sense let me know and I'll set up and example.
Also, from your example it sounds like you might want to look into "iTween Move Update". Instead of moving from one specific place to another, it lets you update your move conditions each game cycle. This is useful if your moving object is trying to track another moving object. If you use a standard "move to", the mover will move to the position the target was at when the action was started, but the target could be long gone by then!