Iraq conflict: All options open to fight insurgents – Obama
US President Barack Obama says his government is looking at "all options," including military action, to help Iraq fight Islamist militants, the BBC reported.
But the White House also insisted it had no intention of sending ground troops.
The remarks came after the cities of Mosul and Tikrit fell to Sunni Islamist insurgents during a lightning advance.
The US has begun moving defence contractors working with the Iraqi military to safer areas.
"We can confirm that US citizens, under contract to the government of Iraq, in support of the US Foreign Military Sales (FMS) programme in Iraq, are being temporarily relocated by their companies due to security concerns in the area," state department spokesperson Jen Psaki said.
Several hundred were being evacuated from Balad air base to Baghdad, a US defence official told AFP.
Led by the Islamic State in Iraq and the Levant (ISIS), the insurgents are believed to be planning to push further south to the capital, Baghdad, and regions dominated by Iraq's Shia Muslim majority, whom they regard as "infidels."
Unconfirmed reports on Thursday said Iraqi forces had launched air strikes on Mosul and Tikrit targeting the militants.
Correspondents say that if ISIS can hold Mosul and consolidate its presence there, it will have taken a giant step towards its goal of creating an Islamist emirate that straddles Iraq and Syria, where insurgents control a large swathe of territory.
Fears of ISIS sparking a wider Sunni uprising have increased with reports that former Baath Party members loyal to Saddam Hussein have joined forces with the jihadists.
One resident in Tikrit, Saddam Hussein's former hometown, told the AP news agency that fighters raised posters of the former dictator after driving the army out.
The United Nations Security Council said on Thursday it unanimously supported Iraq's government and people in their "fight against terrorism."
Earlier it said the humanitarian situation around Mosul, from where up to 500,000 people have fled, was "dire and... worsening by the moment."
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