If you have a driver's license from another country, you don't need to have an International Driving Permit, but it is useful. The permit verifies in multiple languages that you have a valid driver's license. Police officers who cannot read the language of their foreign driver's license will be able to read the permit.
and what if my license was issued outside the US?
You must apply for a new original New York State driver's license at a DMV office. See Get a driver's license
What if I have a New York State learner's permit or one issued in another state?