"The changes we're pursuing can be described by what I call the 'three R's' — Raqqa, Ramadi and Raids," Carter testified to the Senate Armed Services Committee. 

The secretary also said he hopes to pursue the new approach of equipping what he called the “Syrian Arab Coalition”, which consists of about a dozen groups, versus the halted Pentagon program to train and equip a force of 15,000 rebels over three years.

"While the old approach was to train and equip completely new forces outside of Syria before sending them into the fight, the new approach is to work with vetted leaders of groups that are already fighting ISIL and provide equipment and some training to them and support their operations with airpower," he said. 

He also said the coalition expects to intensify its air campaign with additional U.S. and coalition aircraft and to target ISIS with a higher and heavier rate of strikes.

Second, Carter said "Ramadi" represents an example of cooperation with Iraqi forces and Sunni tribes to retake and hold ground from ISIS.

"As we see more progress toward assembling capable and motivated Iraqi forces under Baghdad’s control and including Sunni elements, we are willing to continue providing more enabling capabilities and fire support to help our Iraqi partners succeed," Carter said.

Carter said the third "R" — raids — represents a new willingness to conduct more raids to support partners or unilaterally.

"We won’t hold back from supporting capable partners in opportunistic attacks against ISIL, or conducting such missions directly, whether by strikes from the air or direct action on the ground," he said. 

Although the two sides signed a document to avoid mid-air collisions over Syria, it does not represent cooperation and would not affect U.S. airstrikes against ISIS, he said.