The United States has expanded sanctions on Syrian President Bashar al-Assad's top defense and security officials, the government said Friday. The Treasury Department said it has placed the Syrian defense ministers, the deputy chief of staff of the army, and Assad's chief on a list that freezes any assets they may have in U.S. jurisdictions and bars Americans from doing business with them. The move was aimed at “those who stand with the Assad regime as it trains the instruments of war against Syrian civilians,” Treasury said in a statement. Assad and others in his inner circle have already been sanctioned by the United States.