Defense Secretary Ash Carter today revealed that the U.S. will openly begin “direct action on the ground” against ISIS forces in Iraq and Syria.

In his testimony before the Senate Armed Services committee on Tuesday, Carter said “we won’t hold back from supporting capable partners in opportunistic attacks against ISIL…or conducting such mission directly, whether by strikes from the air or direct action on the ground.”

Carter pointed to last week’s rescue operation with Kurdish forces in northern Iraq to free hostages held by ISIS.

Acting on a tip that dozens of ISIS-held hostages were about to be slaughtered, U.S. and Kurdish commandos stormed a prison in northeastern Iraq before dawn Thursday, rescuing the captives in a firefight that ended with Master Sergeant Joshua Wheeler being shot to death, officials said.

Wheeler of Roland, Oklahoma, a highly-decorated soldier and father of four, rushed into action when he heard sounds of gunfire coming from a prison in Iraq where dozens of ISIS-held hostage were being held by ISIS.

At the time Carter and Pentagon officials refused to characterize the operation as U.S. boots on the ground. However, Carter said that the military expects “more raids of this kind” and that the rescue mission “represents a continuation of our advise and assist mission.”

This may mean some American soldiers “will be in harm’s way, no question about it,” Carter said last week.

After months of denying that U.S. troops would be in any combat role in Iraq, Carter late last week in a response to a question posed by NBC News, also acknowledged that the situation U.S. soldiers found themselves in during the raid in Hawija was combat.

“This is combat and things are complicated,” Carter said.

A feisty Sen. Lindsey Graham, R-South Carolina, said on Tuesday that the U.S. effort in Syria is a “half-assed strategy at best,” and said that the U.S. is not doing a “damn thing” to bring down Syrian President Bashar Assad’s regime.

Carter on Tuesday pushed back against that notion.

Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, acknowledged that the “balance of forces” has tilted in Assad’s favor.

This story originally appeared on NBCNews.com