The United States on August 18 designated the spokesman for the Islamic State group as a terrorist.
The State Department also applied the designation to a militant who fled house arrest in France and joined the Al-Qaeda-linked group Nusra Front in Syria.
The actions prohibit Americans from doing business with Abu Mohammed al-Adnani, who was born in Syria, and Algerian-born Said Arif, and freezes all property they have within U.S. jurisdiction.
Both recently were added to the United Nations' terrorist list, requiring all member states to impose an assets freeze, travel ban, and arms embargo against the two.
The move aims to weaken the Islamic State -- an Al-Qaeda splinter group that has seized swaths of territory in Iraq and Syria and declared a caliphate -- and Al-Qaeda's Syrian wing, Nusra Front.