The designation, authorized under Executive Order 13224, targets terrorists and supporters of terrorists or acts of terrorism. The State Department described the terrorist acts committed by al-Adnani in its Monday announcement.
"Abu Mohammed al-Adnani, born Taha Sobhi Falaha in Syria, is the official spokesman for and a senior leader of ISIL. Al-Adnani is ISIL's main conduit for the dissemination of official messages, including ISIL's declaration of the creation of an Islamic Caliphate. Al-Adnani was one of the first foreign fighters to oppose Coalition forces in Iraq before becoming ISIL's spokesman."
The designation bars U.S. persons from doing business with al-Adnani, and any property he holds within the U.S. will be frozen.
Al-Adnani has also been added by the United Nations to U.N. Security Council Resolution 2170, an al-Qa'eda Sanctions list that requires all U.N. member states to freeze any assets associated with al-Adnani and impose a travel ban and arms embargo against the IS spokesman.