The United States imposed sanctions Wednesday on supporters of Syrian President Bashar al-Assad's government, including a middleman it alleged buys oil for the regime from the Islamic State group.

"The Syrian government is responsible for widespread brutality and violence against its own people," said Adam Szubin, acting under secretary for terrorism and financial intelligence, in a statement announcing the sanctions action. "The United States will continue targeting the finances of all those enabling Assad to continue inflicting violence on the Syrian people.”