Hillary Clinton said Tuesday she opposes any formal agreement with Iran in hopes of stopping the sectarian violence in neighboring Iraq.

The possibility of such a deal with the rogue nation surfaced after the militant group the Islamic State in Iraq and Syria (ISIS) last week surged through northern Iraq, taking Mosul and Tikrit. The Al Qaeda offshoot group then advanced toward the capital city of Baghdad over the weekend, overtaking government forces along the way.

“I’m not in favor of any formal agreements with Iran at this time,” Clinton, a former secretary of State and potential 2016 presidential candidate, told Fox News on Tuesday.

Iran’s Shiite regime is a close ally of Iraq Prime Minister Nouri al-Maliki and his Shiite-led government. At the same time, the United States has a shared interest in stopping the ISIS fighters in Iraq, where U.S. troops fought and died for roughly eight years to overthrow the regime of then-President Saddam Hussein.

ISIS fighters have reportedly killed hundreds of Shiites in their run across Iraq.

Clinton suggested the United States try to “persuade or basically bargain” with al-Maliki to get him to run a more inclusive government.

However, she put little faith in him.

“If I were Iraqi, I would be thinking hard about -- Do I want Maliki to continue to be prime minister?” said Clinton during an interview with Fox’s Bret Baier and Greta Van Susteren.

“He has failed as leader, purged the military, rearranged the government, gone after Sunnis. That is (a) recipe for continuing instability.”

Clinton also suggested that al-Maliki would not leave easily.

Secretary of State John Kerry on Monday raised the possibility of a deal when he told Yahoo News that the administration was discussing the idea.

In addition, the State Department has said Deputy Secretary William Burns talked briefly on the sidelines of nuclear talks in Vienna about the situation. However, the Pentagon said Monday the Defense Department has no active plan to work with Iran in Iraq.