Abu Sayyaf was described by one official as the ISIS "emir of oil and gas," although he also was targeted for his known association with the group's leader, Abu Bakr al-Baghdadi.
U.S. House Speaker John Boehner, in a written statement Saturday praising the raid into Syria, said he was "gravely concerned" by the IS assault on Ramadi and that it threatened the stability and sovereignty of Iraq.
ISIS has made major inroads at Iraq's Beiji oil refinery complex in recent days. Reports vary, but U.S. officials have said ISIS is largely in control of the refinery, as well as the nearby town of Beiji. It's on the main route from Baghdad to Mosul, the main ISIS stronghold in northern Iraq.
"We have warned the Assad regime not to interfere with our ongoing efforts against ISIL inside of Syria," Meehan said, using another acronym for ISIS. "As we have said before, the Assad regime is not and cannot be a partner in the fight against ISIL. In fact, the brutal actions of the regime have aided and abetted the rise of ISIL and other extremists in Syria."