Bluskis
In the USA, you don't need a radio operator's licence at all (or didn't last time I checked) to fly an N-reg aircraft.
If you fly an N-reg outside the USA, then you need a radio operator's licence. The procedure for getting one is on the FCC (not FAA) website.
There used to be a "Restricted Radio Licence for an Alien" or some such, free, valid three years. That's all stopped now, and depending on how you fill in the form, it can cost you from $50 to several hundred $. There is no test, no competence requirement, just money.
I got one, valid for life, for $50. It was quite a palaver since I don't have a US Social Security number. I had to fill in various forms to get past the next stage, but it can be done.