What countries do you mention?
As far as I know, I don't think you can get a vehicle insurance for the rest of the world. If you called an insurance company and got a quote, they probably did not understand that you want to ride in Colombia, Pakistan or wherever. Maybe there is a company that provides sush liablility coverage (I can only think of Lloyd's in London), but I wouldn't bet on it.
The reason is local legislation and enforcement of that legislation. Everywhere it's different and to provide even liability insurance for the whole world would be a legal nightmare. On the other hand it might also be a good profit source, but then the insurance would most definitely be astronomically high.
As for regions like North America, Europe, Australia, New Zealand, etc., it's probably possible to get at least liability coverage. Again, it's the relative ease with which laws are enforced and the similarity of them throughout those regions (traffic laws that is), that make it easier for the insurance company to calculate their risk, and consequentely the premium.
I've read from other traveller's that you can buy liability insurance at the border of some countries, so that might be the easier and cheaper option, than to get an insurance that does all. These countries might even mandate you buy that liability insurance. If this will be any worth in case you get into an accident is another matter, and might depend on local law enforcement.
As for collision damage insurance for you vehicle, probably this might be tougher. The main reason, I think, is risk. Not because of fraud (though maybe that too), but the nature of the trip the company would insure (more likelihood of accidents, etc.).
On the other hand, maybe for Europe and North America you might get collision coverage as a non-resident.
In my opinion, unless you have a brand new very expensive bike, you're probably fine just with liability insurance. Now, this is just my opinion.