UNITED NATIONS - The U.N. Security Council condemned Islamic State militants Friday as Secretary of State John F. Kerry invited Iran to play a helpful role in arresting the group’s momentum in Iraq and Syria.

The 15-member council urged the world to expand support for the new Iraqi government, which sent a representative to the unusual special session devoted to the sudden rise of militants that have laid claim to large areas of Iraq and Syria.

“There is a role for nearly every country in the world,” in turning back the militants and debunking their ideology, Kerry said, “including Iran.”

Although the United States worked to exclude Iran from a French diplomatic meeting about the militants on Monday, the United States is trying to encourage the Shiite powerbroker to apply its influence in Iraq and Syria.

Iranian President Hassan Rouhani had dismissed U.S. efforts against the militants earlier this week, and rejected an offer of limited common cause.

The United States and Iran, estranged for more than three decades, find themselves uncomfortably on the same side against the Sunni militants. Iran has military forces on the ground in Iraq, backing the same Shiite-led government that Washington supports. Iran is also backing Syrian President Bashar al-Assad in his fight against both the militants and the U.S.-backed rebels trying to force him from power.

Kerry chaired the session a day after Congress approved the Obama administration’s request to expand the training and arming of Syrian rebel forces.

Iranian Deputy Foreign Minister Abbas Aragchi thanked Kerry for convening the unusual session. Speaking in English, unlike most other Middle Eastern diplomats represented, Aragchi said the Islamic State is “chief among the threats that ravage Iraq and Syria and cast gloom over the Middle East horizons.”

“The Islamic Republic of Iran is the only country in the region that is both capable of and has shown unqualified determination to help the Iraq government,” he added. “We were there with advisers and equipment before any other help arrived on the scene.”

The White House military strategy against Islamic State, also known as ISIL, seeks to use Syrian rebels and Iraqi forces as a ground army, while the United States and other nations attack from the air with missiles and bombs. France joined the ongoing U.S. airstrike campaign in Iraq on Friday, the first nation in a growing military and diplomatic coalition to do so.

Iraqi Foreign Minister Ibrahim al-Jaafari appealed for military and financial support as his country takes on the militants. Iraq inaugurated a new Shiite-headed government this month that has pledged to share power with Sunnis and Kurds. The previous government, which systematically sidelined Sunnis, is blamed for fanning Sunni anger that allowed the Islamic State to flourish and seize territory.

“This major threat should be removed not only from Iraq, but from any other country,” al-Jaafari said.

The council statement expressed “deep outrage” at the campaign of killings and terror waged by the Islamic State, an al-Qaeda offshoot now disowned by the older terror franchise. Some of the group’s actions may constitute war crimes and crimes against humanity, the council statement said.

Kerry called the Islamic State unique in its brutality, and invoked the videotaped beheadings of two Americans and a Briton in recent weeks. The killings have galvanized American public opinion to confront the militants, at least through airstrikes.

“ISIL simply poses a threat to the people of Iraq and Syria and the broader Middle East,” Kerry said, using an alternate acronym for the group. “And if left unchecked, these terrorists certainly would pose a growing threat beyond the region because they have already promised it.”