The U.S. special operation forces that will soon be deployed to Iraq are tasked, among others, with capturing senior leaders of the Islamic State (ISIS) on a mission to learn more about ISIS networks, U.S. military officials revealed.

"This intel gathering mission is just as important, if not more important, than killing bad guys," one official told Fox news.

In making the announcement on Tuesday, U.S. Defence Secretary Ashton Carter said the U.S. special forces will "put further pressure'' on ISIS.

Approximately 200 U.S. commandos, including intelligence personnel, pilots to position them, mechanics to maintain their aircraft, a quick reaction force and other support personnel in addition to the main assault force are headed to Iraq as part of the new "specialised expeditionary targeting force,'' Carter told the House Armed Forces Services Committee hearing, according to Fox News.

"In full coordination with the government of Iraq, we're deploying a specialised expeditionary targeting force to assist Iraqi and Kurdish Peshmerga forces,'' Carter said.

"They would carry out raids, free hostages and capture IS leaders. They would also conduct unilateral operations in Syria, '' he said, adding that the raids will be conducted at the invitation of the Iraqi government, and that the forces would also be able to launch operations into Syria.

Carter noted that the move would allow the U.S. to gain ground intelligence, enhance air capabilities and allow local forces to gain and hold ISIS-occupied territory.

The new mission was announced after President Obama made a statement saying that the ISIS has been contained.

In his remarks last Nov. 12, just one day before ISIS terrorists launched their deadly attacks on Paris, Obama said: "I don't think they're gaining strength. What is true is that from the start our goal has been first to contain, and we have contained them. They have not gained ground in Iraq. And in Syria, they'll come in, they'll leave, but you don't see this systematic march by [ISIS] across the terrain.''

In the same hearing on Tuesday, Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff told Rep. Randy Forbes, R-Virginia that the ISIS has yet to be contained, contradicting Obama's claim.

The White House later clarified that they were able "to halt the [geographic] expansion of the group which had been on the march in both Syria and Iraq for sometime.''

Dunford also clarified at the hearing that Pentagon chiefs only began meeting with top White House officials to discuss certain aspects of the ISIS strategy a couple of months ago, the Washington Times reported.

Since 2014, the terror group has seized large swathes of Iraq and Syria. The U.S.-led coalition has been conducting air campaign against the ISIS in both countries. Russia has focused its airstrikes in Syria.