WASHINGTON — The Obama administration is willing to talk with Iran over deteriorating security conditions in Iraq and is not ruling out potential U.S.-Iranian military cooperation in stemming the advance of Sunni extremists, Secretary of State John Kerry said today.

Kerry also said in an interview with Yahoo! News that U.S. drone strikes “may well” be an option.

Kerry said Washington is “open to discussions” with Tehran if the Iranians can help end the violence and restore confidence in the Iraqi government. Asked about possible military cooperation with Iran, Kerry said he would “not rule out anything that would be constructive.” However, he stressed that any contacts with Iran would move “step-by-step.”

Officials said earlier there is a possibility that Undersecretary of State William Burns may discuss Iraq with an Iranian delegation in Vienna.

“We’re open to discussions if there is something constructive that can be contributed by Iran, if Iran is prepared to do something that is going to respect the integrity and sovereignty of Iraq,” Kerry said.

The Obama administration is also considering unilateral airstrikes to slow an al-Qaida-inspired insurgency.