I wish this was possible. Any time I list an item, it doesn't matter if I mark it US shipping only, and no matter how many times I put in the description that I ship US only, I get flooded with people from other countries asking, "How much to ship to {$nation}?"
After a while I got tied of telling them I don't ship to wherever they are, and just told them that international shipping rates are listed in the description. (Which they aren't, just the note saying no international shipping.)
Then I just started ignoring the bombardment.
Then I just stopped listing stuff on eBay.