To prolong American presence and influence in Iraq, U.S. president authorizes up to 450 additional US troops to help training efforts in Iraq. The additional U.S. troops would join the roughly 3,100 American troops already in Iraq, currently training about 3,000 Iraqis.

But whether they can is an open question. And Republican lawmakers say the Obama administration still lacks a coherent strategy that can reverse ISIS gains.

"I don't think 450 troops are going to make the difference," Rep. Adam Kinzinger, R-Ill., told Fox News, while still calling Wednesday's announcement a "good start."

At the Pentagon, spokesman Col. Steve Warren told reporters the 450 additional U.S. forces would be fully up and running in six-to-eight weeks. The new U.S. troops will go to Taqaddum Air Base in Anbar, in the city of Habbaniyah — between Ramadi and Fallujah, both under ISIS control.