Shiite Muslim Iran was so alarmed by Sunni insurgent gains in Iraq that it may be willing to cooperate with Washington in helping Baghdad fight back, a senior Iranian official said.
The idea is being discussed internally among the Islamic republic's leadership, the senior Iranian official said.
Iran will send its neighbour advisers and weaponry, although probably not troops, to help its ally, Prime Minister Nouri al-Maliki, check what Tehran sees as a profound threat to regional stability, officials and analysts say.
"We can work with Americans to end the insurgency in the Middle East," the official said, referring to events in Iraq. "We are very influential in Iraq, Syria and many other countries.
"The danger of extremist Sunni terrorist in Iraq and the region is increasing ... there have been several high-ranking security meetings since [Thursday] in Tehran," the official added. "We are on alert, and we also follow the developments in Iraq very closely."
Relations between Tehran and Washington have improved modestly since last year's election of President Hassan Rowhani, who promised "constructive engagement" with the world. "Today, in our region, unfortunately, we are witnessing violence, killing, terror and displacement," Rowhani said on Thursday.