Former secretary of state Hillary Clinton is raising cautions about the United States working with Iran to combat fast-moving Islamic insurgents in Iraq.
Clinton says she is "not prepared" to support the U.S. going in with Iran until the country knows what it's getting into.
The U.S. and Iran have held an initial discussion about how the longtime foes might cooperate to address the threat from the al-Qaida-linked militants that have swept through Iraq.
The potential 2016 Democratic presidential candidate said at a CNN town hall meeting that any alliance with third parties such as Iran needs to be "carefully thought through."
Clinton also praised the capture of a Libyan militant suspected in the deadly Sept. 11, 2012, attack in Benghazi, Libya.