Yes its possible, but you have to put considerable amount of money down. For Turkey, if you really search, you might be able to find a bank that will loan with 30% down, but I think you will probably find its going to be 40% down in alot of places. DTI will have be be under 36%. And you will probably find that the maximum amortization is 20-25 years. Also...(this is where it gets weird) international mortgages will not let you have 20-25 years amortization depending how close you are to 70 years old. So say you are 65...they will only give you 5 years amortization. If you are 55, they will only give you 15 years amortization.
Also, you will probably have to have something like 6 months to a years mortgage payments held in an account and the account needs to be opened in that country and usually running for about 6 months (of course there are exceptions).
I would google "international mortgage broker" and sort though all those sites. You will probably pay slightly higher interest rates though for being in another country.