If you do not have any loan documents, the money you receive will be treated as a Gift. If the money you receive is in the form of a gift, it will be 100% tax free, if it does not exceed the annual exclusion limit. You are not subjected to any taxes but you are required to report the money to the IRS if it is more than USD100,000, or received any interest from the loan or received from a non resident.
If you have the loan document, US taxes on the interest will be applicable even if there is no interest received.
You may be subjected to gift tax in the US.
Discuss with your tax advisor or consult a CPA or tax attorney for any tax related questions.