It used to be just a matter of walking into an FAA district office with a valid ICAO licence and walking out a while later with a temporay airman's certificate.
But recent events have now complicated matters.
AIUI you must first apply to your local aviation authority to release your details to the FAA.
You then apply to the FAA for a licence to be issued based on your foreign licence.
After getting a reply you then book an appointment with a FSDO in the US.
Get interviewed and walk out with a temporary airman's certificate valid for 120 days.
Validate it with a BFR and your away.
A permanent Certificate will eventually arrive at your home address.
The minimum licence level is an ICAO compliant PPL (i.e. valid for international flight)
As it's based on your foreign licence, that must be fully valid i.e medicals current etc.
