WASHINGTON, D.C. — U.S. Defense Secretary Ash Carter, while testifying before the Senate Armed Services Committee on Tuesday, indicated that the death of Delta Force Master Sgt. Joshua L. Wheeler in Iraq will probably not be the last American ground combat fatality in that country.

On Friday, Carter said he expected the U.S. to conduct more ground raids in support of partners or unilaterally to rescue Iraqi hostages from the Islamic State (ISIS/ISIL) — similar to the one that led to the death of Wheeler.

“We won’t hold back from supporting capable partners in opportunistic attacks against ISIL or conducting such missions directly,” reiterated Carter when testifying before the Senate Armed Services Committee. “Whether by strikes from the air or direct action on the ground.”

“Last week’s rescue operation was led by Iraqi Kurdish forces, with U.S. advisers in support,” he continued in written testimony. “One of those U.S. accompanying advisors, Master Sergeant Joshua Wheeler, heroically acted to ensure the overall success of the mission and lost his life in the process.”

Wheeler became the first U.S. combat fatality in Iraq since 2011 and his death marked the first time American troops had engaged in direct ground combat there since the war against ISIS was launched in August 2014.

“The death of any service member is a tragedy… While our mission in Iraq is to train, advise and assist our Iraqi partners, in situations such as that operation where we have actionable intelligence and a capable partner force, we want to support our partners and we will,”  Carter told Senators on Tuesday.

Sen. Tim Kaine (D-VA) asked Carter, “Is it fair to assume, you know we pray that this is not the case, but that the death of Master Sgt. Wheeler may not be the last death of an American service member in this campaign to defeat ISIL?”

“I think we need to be realistic… our people will be in positions, they are right now everyday, there are people flying right now, there are people training and advising forces there and they’re in harms way,” he responded. “There’s no doubt about it.”

Carter noted that the Delta Force hero “was killed in combat.”

“We’ve lost service personnel before Master Sgt. Wheeler, not necessarily in direct combat or kinetic activities, but as you say they were in positions of danger because of their support for this mission against ISIL,” Kaine told the Pentagon chief.

“Yes, make no mistake. They are in harm’s way in this fight against ISIL,” Carter told Kaine. “No doubt about it.”

Master Sgt. Wheeler died last Thursday of injuries he sustained while assisting Iraqi Kurdish Peshmerga fighters in a raid to rescue 70 hostages from ISIS whose graves had already been dug and were about to be executed. The Pentagon chief declared Friday that he expected the U.S. to participate in more such raids, noting that it is a component of what the Pentagon refers to as a “train, advise, and assist mission in support of Iraqi forces.”

“It doesn’t represent us assuming a combat role. It represents a continuation of our advise and assist mission,” noted the U.S. defense secretary at the time.

However, he later added, “This is combat; things are complicated.”

During the hearing, Carter outlined what he described as the U.S. strategy to intensify military efforts against ISIS.

He said the strategy boils down to “what I call the ‘three R’s’ — Raqqa, Ramadi and Raids.”

In particular, the American military will support so-called moderate Syrian opposition forces as they fight to retake Raqqa, ISIS’ de facto capital in Syria. The U.S.-led coalition is also backing Iraq’s security forces in Ramadi, the capital of Anbar province in Iraq. The U.S. efforts also include robust airstrikes while Russia is also conducting an air campaign against ISIS in Syria.

Carter also suggested that the U.S. will be stepping up “raids” against ISIS, which could include more ground missions.

President Obama vowed not to deploy U.S. ground troops into combat against ISIS.