Yes. Apple aknowledges this in this document: http://www.apple.com/legal/export.html
PROHIBITED DESTINATIONS
The U.S. holds complete embargoes against Cuba, Iran, North Korea, Sudan, and Syria
The exportation, reexportation, sale or supply, directly or indirectly, from the United States, or by a U.S. person wherever located, of any Apple goods, software, technology (including technical data), or services to any of these countries is strictly prohibited without prior authorization by the U.S. Government. This prohibition also applies to any Apple owned subsidiary or any subsidiary employee worldwide.
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For assistance with the US Export Administration Regulations or for help determining your export compliance obligations (including licensing requirements), visit the US Department of Commerce, Bureau of Industry and Security’s web page at http://www.bis.doc.gov/.