US sends 130 more military advisors to Iraq - Hagel

San Diego - The United States has sent 130 more military advisors to northern Iraq to assess the scope of the humanitarian crisis there, US Defence Secretary Chuck Hagel said on Tuesday.

"I recommended to the president and the president has authorised me to go ahead and send about 130 new assessment team members up to northern Iraq in the Arbil area to take a closer look and give more in-depth assessment of where we can continue to help," said Hagel.

A US defence official said the temporary additional personnel would also develop other humanitarian assistance options beyond the current airdrop effort in support of displaced Iraqi civilians trapped on Mount Sinjar by Islamic State militants.

Hagel added: "I would also say that this follows the criteria that President Obama has made very clearly that this is not any extension of any role other for the United States than to find ways to assist and help advise the Iraqi security forces.

"As the president has made very clear, we're not going back to Iraq in any of the same combat mission dimensions that we once were in."

The additional personnel comprise Marines and special operations forces, the defence official said.