The United States is sending 130 military advisers to Iraq to help combat the Sunni Islamists in the Kurdish region and to assist the rescue operations in the Sinjar Mountain, Defence Secretary Chuck Hagel has said.
Hagel insisted this is not a military intervention by American troops but an effort to assist the Iraqi security forces.
"Very specifically, this is not a combat boots on the ground operation. We are not going to have that kind of operation. But short of that, there are some things we can continue to do and we are doing," Hagel told reporters from the Camp Pendleton, a Marine base in California.
There are already 250 US military personnel in Iraq.
Another US defence official, speaking on condition of anonymity, told reporters that the additional special advisers are Marines and special operation forces who will take part in the rescue mission in Sinjar, Al Jazeera reported.
The European Union has also authorised individual members of the bloc to send military aid to Kurdish and Iraqi security forces to fight the militants of the Islamic State, formerly known as Islamic State of the Iraq and the Levant (Isis).
"The [envoys] noted the urgent request by the Kurdish regional authorities to certain member states for military support and underlined the need to consider this request in close coordination with the Iraqi authorities," a statement from the office of EU foreign policy chief Catherine Ashton said.
Countries such as France, Italy and the Czech Republic are in favour of delivering weapons to the Iraqi security forces, despite strong opposition from other EU members. Henceforth, it is not clear whether or when the countries would start sending weapons.