Story highlights Official: Contractors evacuated from Iraq base "due to security concerns"

Iraqi foreign minister says takeover of Mosul is a "major security setback"

The Iraqi army is now in full control of the city of Tikrit, state media reports

U.S. considering host of options in Iraq, but not ground troops

As radical Islamist militants surged through Iraq -- and threatened its capital -- U.S. President Barack Obama conceded the turbulent situation demanded significant assistance immediately and over the long-term for the Baghdad-based central government.

"It's going to need more help from us, and it's going to need more help from the international community," Obama said Thursday. "... I don't rule out anything because we do have a stake in making sure that these jihadists are not getting a permanent foothoold in either Iraq or Syria."

The jihadists he is referring to belong to the Islamic State in Iraq and Syria, or ISIS , which wants to establish an Islamic caliphate, or state, in the region. It's already had significant success to date in Syria, where it has been engaged in the civil war against President Bashar al-Assad's government, and in Iraq, where its fighters recently took over the nation's second-largest city of Mosul.

On Thursday, ISIS spokesman Abu Mohammed al-Adnani purportedly could be heard in an audio recording posted on the group's media website. CNN cannot confirm the authenticity of the 17-minute audio statement or the time of its recording.

The voice implores fighters not to "give up a hand's width of ground you've liberated," as well as to expand the campaign.

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"Continue your march as the battle is not yet raging," the man says. "It will rage in Baghdad and Karbala. So be ready for it."

The militants' march has caught the world's attention. That includes the United States, which led the 2003 invasion that resulted in the toppling of longtime leader Saddam Hussein. Since then, Iraq has seen instability and violence, though none, in recent years, rivals what is happening now.

As to what Washington may do to combat the Islamists, U.S. officials discussed bolstering ongoing efforts to send arms, equipment and intelligence information to help Iraq and its military.

Air strikes are among the options being considered, White House spokesman Jay Carney said. But there won't be a repeat of a large U.S. troop presence on Iraqi soil.

"We are not contemplating ground troops," Carney said. "I want to be clear about that."

Iraq government says it's taken back Tikrit

After days of news about its sometimes sudden, surprising defeats, Iraq's government claimed a key victory on Thursday.

Tikrit, Hussein's hometown, was under full control of the military Thursday, state-run Iraqiya TV said. Just a day earlier, it appeared largely to have fallen to the militant fighters.

The Iraqi military carried out airstrikes overnight, targeting the al-Ghazlany military base, just five kilometers south of Mosul where a group of ISIS militants are believed to be based, the Iraqi Defense Ministry said in a statement Thursday.

Speaking in London, Iraqi Foreign Minister Hoshyar Zebari told CNN on Thursday that the government has "taken a number of steps to push back the terrorists" but that the takeover of Mosul had been a "major security setback."

He said the Iraqi army in the city had "collapsed, basically," and commanders were fleeing north.

"The government has to take a ... serious look at the makeup and the doctrine of the new Iraqi armed forces. You cannot run a country with such commanders."

But Zebari also said there were "already indications" the militants were pulling out of Mosul, adding that the government was working with Kurdish regional powers to push them out.

His statements were made as footage surfaced on social media sites Thursday purportedly showing ISIS militants parading heavy artillery through Mosul.

Iraqi official: Nobody has called for U.S. troops

Zebari declined to give a clear answer when asked what assistance Iraq had requested from the United States.

But he said, "Nobody has called ... for the introduction (of) American troops into Iraq."

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Photos: Photos: Iraqi civilians flee Mosul Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Iraqi civilians from Mosul escape to a refugee camp near Erbil, Iraq, on Thursday, June 12. More than 500,000 people fled in fear after extremist militants overran Mosul, Iraq's second-largest city, on June 10, the International Organization for Migration said. Hide Caption 1 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Iraqi refugees pass an area in Erbil on June 12. Hide Caption 2 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Young refugees sleep in a tent at a temporary camp in Aski Kalak, Iraq, on June 12. Hide Caption 3 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – A girl from Mosul stands outside her family's tent at a refugee camp near Erbil on Wednesday, June 11. Hide Caption 4 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Families gather at a checkpoint in Iraq's Kurdish region on June 11. Hide Caption 5 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – A man in a wheelchair is among those fleeing the violence on June 11. Hide Caption 6 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – A security guard is seen at a Kurdish checkpoint on June 11. Hide Caption 7 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Construction begins on refugee camps in Erbil on June 11. Hide Caption 8 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Vehicles clog a highway as refugees flee Mosul on Tuesday, June 10. Hide Caption 9 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Refugees are seen in Erbil on June 10. Hide Caption 10 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – People believed to be refugees flee Mosul on June 10. Hide Caption 11 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Iraqi families are given water as they gather at a Kurdish checkpoint on June 10. Hide Caption 12 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – The rush from Mosul led to bottlenecks at checkpoints as people tried to reach safety in Erbil, about 90 kilometers (56 miles) to the east. Hide Caption 13 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Many people are fleeing on foot. Mosul's four main hospitals are inaccessible because of fighting, and some mosques have been converted to act as clinics, the International Organization for Migration said. Hide Caption 14 of 15 Photos: Photos: Iraqi civilians flee Mosul Iraqi civilians flee Mosul – Iraqi police stand guard at a checkpoint in Baghdad. Hide Caption 15 of 15

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Zebari said Washington has been cooperative and has a responsibility to be proactive in Iraq's fight against terrorism.

The United States has helped and can help with "a whole range of options," including counterintelligence training and supplying equipment and munitions, he added.

Iraq's parliament failed to hold an emergency session Thursday to vote on declaring a state of emergency, as al-Maliki had requested, Iraqiya TV reported.

Some Iraqi lawmakers refused to attend Thursday's session to prevent a quorum.

Their deadlock may be reflective of the increasingly sectarian divide in both Iraq's military and government.

While acknowledging the need for the Shia-dominated government to be more inclusive, Zebari called for lawmakers to rise above divisions and unite in the face of the threat from the Islamic State in Iraq and Syria.

"Really, this is not the time to be involved in these internal political differences," he said. "We are facing a larger threat."

Red Cross: Don't target civilians

While the violence continued, the International Committee of the Red Cross pleaded Thursday that civilians be spared.

"Civilians must not be attacked and they must be allowed to move freely to safer areas," said Patrick Youssef, head of the ICRC delegation in Iraq. "Civilian structures such as homes, hospitals, schools or places of worship must not be targeted."

ICRC personnel in Kirkuk, Dohuk, Irbil and Baghdad are paying close attention the situation, Youssef said, noting that Mosul is enduring power shortages. Hospitals there have the capacity to treat large numbers of people, he said, but some have stopped functioning.

ICRC staff members have distributed one-month food parcels and other relief items to more than 10,000 people displaced in Zummar and in Al-Qosh, north of Mosul. More food and other supplies will be delivered soon, Youssef said. The ICRC is appealing to all the parties involved in the unrest, he added.

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Map: Unrest in Iraq

The International Rescue Committee said it was "deeply concerned" about the displacement of Iraqis fleeing the violence and the Syrian refugees in Iraq who fled fighting in their country.

"The potential toxic brew of two neighboring countries in such a volatile region imploding has grave humanitarian consequences," IRC said Thursday in a statement.

Government open to U.S. strikes on militants

The devastating militant advance, which had been building for some time, is proving an object lesson of much that is wrong in Iraq and the region -- growing sectarian tensions at home and a festering civil war over the border in Syria.

It also shows that extremists can strike swiftly and effectively against Iraq's American-trained security forces.

It came as little surprise when Iraq indicated a willingness Wednesday for the U.S. military to conduct airstrikes against the radical Islamist militants.

Washington has provided $15 billion in training, weapons and equipment to the Iraqi government.

But U.S. officials said the situation is "extremely urgent," and the United States is looking to see what more support it can provide Iraq.

Part of the help involves giving Iraq intelligence it can use to go after the militant group.

National Security Council spokeswoman Bernadette Meehan said the White House was looking at a range of options, but "the current focus of our discussions with the government of Iraq and our policy considerations is to build the capacity of the Iraqis to successfully confront and deal with the threat."

When the militants attacked the northern cities of Mosul and Tikrit, government forces took off, leaving their weapons behind.

There clearly was a breakdown in Iraqi security, a U.S. official said. But Washington says it was caused by a combination of factors, including that Iraqi forces were already stretched thin by limited success against ISIS in another province, the insurgency-racked Anbar.

Rapid takeovers

For now, militants remain in control of Mosul, a predominantly Sunni city of 1.6 million that collapsed swiftly Tuesday. The heavily armed radicals overran police stations, freed more than 1,000 prisoners from the city jail and took over the international airport.

Iraqi forces ran in the face of the onslaught, leaving behind uniforms, weapons and armored vehicles.

Since then, more than 500,000 people have fled the fighting there, the International Organization for Migration said Wednesday . The U.N. refugee agency said many left with little more than the clothes on their backs and were in urgent need of shelter, water, food and medical care.

Among those leaving for safety: U.S. contractors at a military base in Balad, about 90 kilometers (55 miles) north of Baghdad.

State Department spokeswoman Jen Psaki said American citizens working on contracts supporting U.S. military sales to Iraq "are being temporarily relocated by their companies due to security concerns."

Their evacuation began early Thursday morning and is ongoing, a U.S. official said. Most of the contractors, some of whom are not American, are being flown out of Iraq -- not to the U.S. Embassy in Baghdad, as an official said earlier. This effort, which does not involve military aircraft, is being conducted by their companies with the U.S. government's help, a senior State Department official said.

The companies involved include Lockheed Martin, spokesman Mike Rein said.

The fate of some 48 people, including diplomats, seized Wednesday in a raid of the Turkish Consulate in Mosul is less clear.

On Thursday, Turkish Foreign Minister Ahmet Davutoglu said during a televised news conference that the health of the Turkish diplomats and nationals who were captured is "fine."

The government will "continue working around the clock and will continue working until they all return home safely," he vowed.

Militants also seized parts of Baiji, a small town where Iraq's largest oil refinery is located

For the government to reinforce its troops in Mosul, it needs to drive them through Baiji. If the Islamic State in Iraq and Syria, controls the town, the government's task will be much harder.

A silver lining?

However, one silver lining, the American officials said, is that Iraq seems to have a coordinated approach with the semiautonomous Kurdish regional government. It appears that Iraqi forces will team up with Kurdish fighters, known as the Peshmerga, to fight the militant group.

Peshmerga forces took up positions in southwest Kirkuk after militants took over areas north and west of the city, and the Iraqi army withdrew, according to police officials there.

Helgort Hakmet, head of the media office of the Kurdistan Peshmerga Ministry, told CNN on Thursday that Kurdish troops now control the entire province of Kirkuk.

Local police forces are still in charge of the security inside the city of Kirkuk, he said, about 165 miles (266 kilometers) north of Baghdad.

The Iraqi government hopes the militants can also be beaten back elsewhere.

"This is not the end, we are very confident that we will be able to correct the path and to overcome mistakes," the Iraqi Defense Ministry said on its website.

Earlier this year, ISIS took control of the city of Falluja and parts of Ramadi. Across the border in Syria, it controls towns such as Raqqa.

It is capable of fighting the forces of Syrian President Bashar al-Assad on one hand, fellow radicals on another and the Iraqi government on top of that -- an indication of the depth to which the group has established itself in the region, experts have said.

On Wednesday, the U.S. State Department updated its travel warning for Iraq. Terrorist activity and violence, it said, are at "levels unseen since 2007."