The weeklong onslaught by a marauding army of Islamist extremists in Iraq pushed the United States and its longtime rival Iran on Monday to discuss collaborating against a common foe, although the White House ruled out any joint military operations.

In another sign of the growing danger, President Obama notified Congress that he was sending up to 275 U.S. military personnel “to provide support and security for U.S. personnel and the U.S. Embassy in Baghdad,” and the United Nations announced that it was moving nearly 60 staff members from Baghdad to neighboring Jordan.

Obama also is considering sending 100 or fewer special operations troops to Iraq to advise its armed forces as it battles the insurgents, according to a senior U.S. official.

After Secretary of State John F. Kerry said the United States was open to working with Iran, his top deputy, William J. Burns, met with Iranian diplomats on the sidelines of nuclear negotiations in Vienna. They discussed possible cooperation to help stop the insurgents, who have unleashed sectarian bloodletting in Iraq and are threatening stability in the Middle East.


Iraqi Prime Minister Nouri Maliki’s government insisted the Sunni Muslim extremists from the Al Qaeda splinter group Islamic State of Iraq and Syria, or ISIS, do not threaten Baghdad, even as the militants extended their grip on an arc of territory that stretches from the city of Aleppo in northern Syria to within 60 miles of the Iraqi capital. ISIS forces captured the strategic Iraqi city of Tall Afar early Monday.

After Obama notified Congress of his intentions, the Pentagon spokesman, Rear Adm. John Kirby, said that about 170 members of the military had already arrived in Baghdad and about 100 more had been moved “into the region to provide airfield management, security and logistics support if required.” Those 270 make up most of the contingent Obama referred to; any special operations forces would presumably be in addition to them.

The special forces team would operate under the U.S. ambassador in Baghdad and would be barred from engaging in ground combat, the senior U.S. official said, speaking on condition of anonymity because he was discussing military planning. If approved by Obama, their mission would include coordinating U.S. airstrikes on insurgent positions, sharing intelligence with Iraqi security forces and giving Iraqi commanders tactical advice, the official said.

The Iranian military is reportedly already advising some Iraqi troops.


Units of Iraq’s U.S.-trained military have largely melted away in the face of the recent insurgent advances, with thousands of government troops reportedly deserting.

Obama, who said Friday that he would ask his national security team to give him options for Iraq, has not yet decided on a plan of action, officials said. Sending special operations forces, even a small detachment, could be seen as a backtrack from Obama’s pledge last week not to put American troops back in Iraq 2 1/2 years after he withdrew all U.S. forces from the country.

Caitlin Hayden, spokeswoman for the National Security Council, would not confirm that special operations troops might go back as advisors, saying only that Americans would not take part in ground combat.

“The president was very clear that we will not be sending U.S. troops back into combat in Iraq,” she said in a statement. “That remains the case, and he has asked his national security team to prepare a range of other options that could help support Iraqi security forces.”


Analysts and military officials said sending U.S. military advisors might prove unavoidable in order to reverse the insurgents’ momentum. Without U.S. experts to guide drones and manned aircraft to targets on the ground, airstrikes may prove ineffective or be more likely to accidentally hit civilians.

A day after ISIS posted graphic images online purporting to show its fighters massacring dozens of captive Iraqi soldiers as they lay helpless and bound, the top U.N. human rights official condemned the group and said its actions appeared to be criminal.

Although the number killed could not be verified, “this apparently systematic series of cold-blooded executions … almost certainly amounts to war crimes,” U.N. High Commissioner for Human Rights Navi Pillay said in a statement from Geneva. She said the U.N. also had received reports that the militants had killed the imam of the Grand Mosque in Mosul, as well as a dozen other religious leaders.

So far, ISIS fighters have not attempted to move on the heavily fortified capital, Baghdad, or the Shiite Muslim-dominated south.


But a government spokesman, Brig. Gen. Saad Maan Ibrahim, indicated that some militants were nearby. Without giving details, Ibrahim told reporters Monday that security forces had killed 56 “terrorists” in the previous 24 hours in clashes just outside Baghdad.

The crisis in Iraq has roiled the entire region and prompted urgent international calls for Maliki to mend political fences and forge national unity against the attackers. Maliki, a Shiite, has been criticized for favoring his sect and excluding Sunnis from posts of power.

With the Iraqi leader insisting that territory lost to the militants would be regained, the government mobilized elite troops, local militias and its air force to try to wrest control of Tall Afar, an ethnically mixed town of about 200,000 people, from ISIS fighters who had captured it overnight.

Tall Afar, about 60 miles from the Syrian border, fell before dawn to ISIS forces who paraded through streets waving their black banners and brandishing weaponry, according to residents and officials. Hundreds of families fled the militants’ advance, some seeking shelter in nearby Kurdish-controlled areas and others making camp in the desert.


The militants claimed Monday that they had captured the military commander in Tall Afar, Gen. Abu Walid, and that he would be executed in public. State television quoted the general as saying he was free and busy on the battlefield, but did not produce any audio or video to show he was not in ISIS custody.

As ISIS appeared to consolidate its gains, Kerry was more explicit than other officials about U.S. willingness to cooperate with Iran to stop the bloodshed.

“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 in an interview with Yahoo News.

Burns, the deputy secretary of State, met with Iranian officials in Vienna on the sidelines of talks aimed at curbing Iran’s nuclear program.


A senior State Department official said the two governments are open to additional meetings to discuss how ISIS “threatens many countries in the region, including Iran, and the need to support inclusivity in Iraq and refrain from pressing a sectarian agenda.”

The White House denied any suggestion that the Pentagon would conduct joint operations with Iranian forces against the insurgents.

“We’re not interested in any effort to coordinate military activities with Iran,” said Josh Earnest, the White House deputy press secretary.

Although U.S. and Iranian officials both back Maliki’s government, they have widely divergent goals. Even informal cooperation between the Obama administration and Iranian President Hassan Rouhani would be highly sensitive in both capitals as well as elsewhere in the Middle East.


America’s closest regional allies, Saudi Arabia and Israel, fear that any alliance to stop the growing bloodletting in Iraq could weaken their strategic position against Iran, their top regional rival.

Analysts say the U.S. and Iran are likely to agree to only limited cooperation at best, if Obama chooses to order airstrikes or other direct military action. Rouhani has publicly pledged to support Maliki, and widespread reports indicate he already has deployed members of Iran’s elite Revolutionary Guard Corps to bolster Iraqi forces.

Washington and Tehran would probably want to share some information or intelligence on their activities to avoid a direct conflict, they say.

ISIS fighters last week overran Iraq’s second-largest city, Mosul. They then captured Tikrit, hometown of the late dictator Saddam Hussein.


They now are menacing Samarra, a Sunni-dominated city about 70 miles north of Baghdad that is home to an important Shiite shrine.

On Monday, state television showed military videos of what it said were Iraqi airstrikes on ISIS targets in and near the city.

Responding to calls from religious and political leaders, Iraqi Shiites have flooded recruitment centers for fighting forces to help defend Samarra and other areas. Maliki vowed late Sunday during a visit to a military headquarters in Baghdad to repel the insurgents.

“The … defeat will not continue,” he said. “There is a sea of men marching to put an end to this.”


Times staff writers Richter and King reported from Vienna and Cairo, respectively, and special correspondent Bulos reported from Irbil, Iraq. Times staff writers David S. Cloud, Christi Parsons and Kathleen Hennessey in Washington contributed to this report.