US President Barack Obama has ordered the deployment of up to 1500 extra troops to Iraq, more than doubling the number already there.
Some of the troops will be dispatched to new camps to train Iraqi and Peshmerga army brigades.
The Obama Administration plans to ask Congress for extra funding to support these training camps.
The Government of Iraq will also make a contribution.
The extra US military personnel will travel to Iraq over the coming months and will have a non-combat roll.
In a statement, Pentagon Press Secretary Rear Admiral John Kirby said the troops would expand the US: "advise and assist mission" and would also be used in a "comprehensive training effort" for Iraqi forces.
The statement said that the extra troops had been authorised at the request of the Government of Iraq.
US Central Command, which is leading the operation in Iraq against the grouping styling itself the Islamic State, will establish two operation centres in the field to advise and assist Iraqi forces.
These will be in locations outside of Baghdad and Erbil, and will be supported by what the Pentagon described as "an appropriate array of force protection capabilities".
Several new training camps will be set up for the US military to train nine Iraqi army brigades and three Peshmerga brigades, in the north, west and south of Iraq.
This latest deployment will bring the number of US military personnel in Iraq to around 2,900.
