The US Treasury Department imposed sanctions on Syria's foreign minister and two other top officials Tuesday. Asset freezes and bans on business interactions were imposed on Foreign Minister Walid Muallem, top presidential advisor Bouthaina Shaaban, and Syrian ambassador to Lebanon Ali Abdul Karim Ali, the Treasury said. "Building on our sanctions targeting the entire government of Syria, we are bringing additional pressure to bear today directly on three senior Assad regime officials who are principal defenders of the regime's activities," said Treasury Under Secretary David Cohen.