The Obama administration on Thursday threatened to slap sanctions on anyone buying oil from Islamic State militants in an effort to disrupt what it said was a $1-million-a-day funding source. Islamic State has seized large swaths of Iraq and Syria in a brutal campaign, and could pose a threat to the United States and its allies if it is not stopped, US Treasury Undersecretary David Cohen said.
"With the important exception of some state-sponsored terrorist organizations, ISIL is probably the best-funded terrorist organization we have confronted," Cohen said, referring to another name for Islamic State. He spoke at the Carnegie Endowment for International Peace.