CIA Director John Brennan on Friday described the battle for Tikrit as "a good example” of the effort to dislodge ISIL from areas they controlled.
"They’re not invincible, they can be stopped and that’s been proven,” Brennan said during an appearance today at the Council on Foreign Relations in New York.
Just last week, Iraq launched a major offensive to retake the northern city of Tikrit with a combined force 25,000 Iranian-backed Shia militia members and Iraqi security forces.
Gen. Martin Dempsey, the chairman of the U.S. Joint Chiefs of Staff, told Congress earlier this week that Iranian-backed Shia militias made up 80 percent of the force pressing towards Tikrit. Warren said there have still been no U.S. airstrikes in support of the Iraqi offensive.
Iran has "certainly brought to bear a number of capabilities” against ISIL, Brennan admitted.
The CIA director said his agency was not working with the Iranians inside Iraq, though both countries have an interest in defeating ISIL.
Brennan said he thought there was "an alignment of some interest between ourselves and Iran, clearly in terms of what ISIL has done there.”
"So we work closely with the Iraqi government, the Iranians work closely with the Iraqi government as well,” he added. "So some of these efforts I think through the Iraqi interlocutors are ones that again are trying to advance our common objectives against ISIL.”
Last year, President Obama reportedly sent a secret letter to Iranian Supreme Leader Ayatollah Ali Khamenei noting the shared interest in the fight against ISIL and said that any cooperation on the effort was dependent on certain components of ongoing talks trying to halt the country’s nuclear program.