Zakaat on Money Returned by a Supplier

Q: If I transferred monies 3 years ago to a supplier overseas, and until now, the supplier has not sent me the goods nor has he returned my money up until now, do I have to pay zakaat on this money. The money is sitting with him 3 years and he might return the money within a month? Do I have to pay zakaat on this money which is not in my possession for 3 years now?