Iraq still under IS threat: Pentagon

US department of defence (DOD) Thursday said the threat from the Islamist militants remain in Iraq even though fear of mass violence on Mount Sinjar has passed.

DOD Press Secretary John Kirby said the situation in Iraq remains dangerous and the US will continue its efforts to assist the Iraqi people caught up in violence, Xinhua reported.

While describing the objectives of the US military mission in the country set forth by President Barack Obama, Kirby said: "The president has been clear about our limited military objectives in Iraq."

"They are, one, to protect American citizens and facilities, two, to provide advice and assistance to Iraqi forces as they battle Islamic State (ISI); and, three, to join with international partners to address the humanitarian crisis," the press secretary added.

The US military remains ready to continue air strikes to protect US personnel and facilities and around Kurdish capital of Erbil and to protect the Yazidi people, Kirby said.

The US Wednesday said that the establishment of humanitarian corridors and airlifts are among options being considered by President Barack Obama to evacuate the Iraqi civilians trapped by the Islamic militants on the mountain.

Earlier Tuesday, US Defence Secretary Chuck Hagel announced the arrival of 130 additional US military advisers in Erbil, where it will help rescue a large group of civilians besieged by the Sunni terrorists of the IS.