Yes. When buying a policy in America you should expect to have an American driver's license or you should expect to get one in order to be insured in America.
There may be some specialty carriers that will insure you in the United States with an international license, but most insurance companies require you obtain a drivers license in the state you reside before purchasing insurance or within 30 days after obtaining coverage.
We don't know of any specific specialty carriers. On our site, you may list that you have an International License, but most carriers won't return a rate unless they know you will get a license in the U.S.
CarInsurance.com will require you to have a license (with some of our carriers) or in the process of obtaining a US license (with some of our carriers). In the states where we offer online quotes, you can get a quote and answer the auto insurance quote questionnaire appropriately.