It depends on the tax laws in your country if you can reclaim already paid tax or get a tax credit when you file your tax return. You should consult a tax advisior in your country!
You country may have a double taxation treaty with the USA, look at this list:
If your country has a treaty, than it is possible that you pay less or no withholding tax if you fill out the W-8 form with your legit TAX ID.