U.S. President Barack Obama has authorized the U.S. military to deploy up to 1,500 more troops to Iraq in a non-combat role as part of the mission to drive back Islamic State militants.
The U.S. military's expanded mission in Iraq will total up to about 3,100 American troops spread across the country.
A senior administration official said the coalition will set up two advise-and-assist operation centers, one likely in Anbar province, an area intensely embroiled in the fight against Islamic State, and another likely in northern Baghdad province.
The official said about 870 of the troops heading to Iraq will help train nine Iraqi force brigades and three Kurdish Peshmerga brigades. The training will take place in Diala, Anbar, Irbil and Baghdad provinces.
Pentagon spokesman Rear Admiral John Kirby said the training mission will take time.
"It's going to take us, probably a couple of months, two to three months, to get the sites prepared and the regimen started. And then the training itself we anticipate, the training regimen itself, to take six-seven months," he said.
Before this order, U.S. troops in Iraq largely stayed at operation centers in Baghdad and Irbil.
The president has asked for more than $5 billion from Congress to fund the mission. Admiral Kirby said the military needs the funding and authorization from Congress in order to carry out the expansion.
The increase has drawn comparisons with the last time U.S. forces were in Iraq between 2003 and 2011. Kirby said Friday, though, U.S. troops are entering a "completely different situation" this time.
"First, we're going in at the request of the Iraqi government. We're wanted there. We weren't wanted to stay there after 2011," he said. "Number two, there's a very acute threat that's facing the Iraqi people, the Iraqi government and Iraqi security forces -- a threat that they are trying to grapple with right now and they have acknowledged that they need a little bit of help in that regard."
With the aid of U.S. air strikes, Iraqi forces have dealt a number of blows to Islamic State militants in recent weeks. Islamic State fighters have lost a string of towns near the Syrian border, and last week, Iraqi forces recaptured the town of Jurf al-Sakher, about 60 kilometers southwest of Baghdad.