May be the rules are different in different states. But in NY state you are not required to get ny state license if you are foreigner and posses a driver license from your contry of origin.

The link below clearly states this.

http://www.nydmv.state.ny.us/license.htm#driversfromothernations

Drivers From Other Nations

Drivers from Canada.

A valid driver license from another country is also valid in NYS. You do not need to apply for a NYS driver license unless you become a resident of NYS.

According to NYS law, a resident of another country can get a NYS driver license. The DMV does not recommend this because:

• NYS recognizes your foreign driver license if you remain a resident of the nation that issued the license. You do not need to have a NYS driver license to drive in NYS unless you become a resident of NYS.
• If you have a driver license from any nation except Canada, you must pass a written test, complete a 5-hour pre-licensing course and pass a road test to qualify for a NYS driver license. See "New Drivers - How to Apply".
• You must show a Social Security Card. If you are not eligible for a Social Security Card, you must provide a letter or form SSA-L676 from the US Social Security Administration (SSA) that states that you are not eligible. The SSA Letter or form must have been issued no more than 30 days before the date of your application. You must also show the U.S. Citizenship and Immigration Services (USCIS) documents that the SSA used to determine that you are not eligible for a Social Security Card.  The USCIS was formerly known as the Immigration and Naturalization Service (INS).  Read the specific requirements on the identification requirements page.
• When you receive your NYS driver license, you must surrender your foreign driver license to the DMV road test examiner. The local DMV office keeps your foreign driver license, and then destroys the license after 60 days. If you plan to return to your home country and use your foreign driver license, ask the road test examiner how to make sure that your foreign driver license is not destroyed. If you need to get your foreign driver license, go to the local DMV office where you applied for your NYS driver license.