Who is the custodian? (Fidelity? Schwab? Vanguard? Other?)
For a Traditional IRA, my understanding is that your withdrawals will be subject to 30% withholding but you will likely be able to recover some of that withholding if/when you file a U.S. tax return (1040NR) -- although it'll take until the next tax filing season to recover. The actual tax owed should be equivalent to what a similarly situated U.S. person would pay. You must start taking withdrawals ("Required Minimum Distributions") no later than age 70 1/2.
Your other choice is a Traditional IRA to Roth IRA conversion, if your custodian will allow it. (It should.) You would pay the tax and file a tax return now, and then future gains/withdrawals would be U.S. tax free. Roths do not have RMDs. I can't remember if the 5 year minimum Roth holding period applies to conversions. You are allowed to convert only some of the funds. For example, you could take some cash in December (see below) and convert the rest.
If the IRA is "small," the major consideration is likely to be the paperwork -- to do that just once, ideally. Another consideration is that you might want to take your withdrawal(s) in December, so that your recovery is as soon as the following February or March. The quicker you can recover excess withholding, the better since you can put that recovered money to work that much sooner.
It depends on what the IRA is holding, but typically it would count toward your U.S. estate tax exemption of US$60,000.
If you're leaning in any particular direction(s), I can take a closer look at it. Those are the general highlights as I understand them.