Earnest said:

"The president and his team are confident that, for now, 450 troops - additional military personnel - are what is necessary to fulfill this expanded advise-and-assist training mission to Takata airbase."

He later added:

"It's hard to give you a real clear sense of exactly what other things are on the table. The president has been clear about what's not on the table - and that is a large-scale ground combat operation inside of Iraq. The reason the president has ruled out that option is the president does not believe it is in the national security interest of the United States for us to do for the Iraqi's what they must do for themselves."

The deployment will bring the number of U.S. troops in Iraq to nearly 3,500.

Earlier this week, President Obama noted that the U.S. does not have a complete strategy for addressing the presence of ISIS militants in Iraq. During the G7 Summit, Obama said, "As soon as a finalized plan is presented to me by the Pentagon, then I will share it with the American people. We don't yet have a complete strategy because it requires commitments on the part of the Iraqis as well about how recruitment takes place, how training takes place, so the details of that are not yet worked out."

ISIS made its advance into Iraq nearly one year ago and still holds large swaths of the western part of the country.

Photo Source: Groundreport.com