Outgoing US Defense Secretary Chuck Hagel has acknowledged that neutralizing Islamic State in Iraq may require American troops on the ground with non-combat roles, such as gathering intelligence and locating targets.

All options must be considered, Hagel said in an interview to CNN.

“I think it may require a forward deployment of some of our troops,” said Hagel as quoted by the ABC News. “Not doing the fighting. Not doing the combat work that we did at one time for six years in Iraq. We did for many many years in Afghanistan. But to help airstrike precision... locate. Those are things where we could continue support.”

“It could be necessary," he said. "It could be, but I’m not willing to say that it will be necessary.”

"Whether we get there or not, I don’t know whether that’s something our military commanders recommend into the future, I don’t know," the outgoing Defense Secretary stressed.

Last November, Hagel insisted that Americans “will not be engaged in a ground combat mission.”

Such troops would not explicitly take on a fighting role, though, but, according to him, assist local forces in situations where maneuvering against the Islamic State militants on their own would be problematic.

READ MORE: Boots on the ground: Pentagon ‘certainly considering’ new role for US troops in ISIS fight

As of now, the US have 4,500 troops in Iraq for training and advising Iraqi military, Reuters reports.

To fight Islamic State (also known as ISIS, or ISIL) effectively, Iraq will require roughly 80,000 US-trained local forces, Joint Chiefs of Staff Chairman Gen. Martin Dempsey acknowledged at a Congress hearing in November.

READ MORE: Obama authorizes 1,500 more troops to Iraq

According to Dempsey, the estimated core of Islamic State forces consists of upward of 18,000 extremists, with probably 31,000 militants in all fighting alongside those forces.

In August 2014, President Barack Obama authorized targeted airstrikes of the US Air Force against ISIS to halt advancing Islamic State convoys and to save Yazidis and Christians units battling IS. The US president also said that Washington is prepared to take“targeted military action” in the form of airstrikes if they are deemed necessary to protect American personnel in Erbil – where a US consulate is located – as well as the embassy in Baghdad.

READ MORE: Obama authorizes airstrikes in Iraq to 'protect US personnel'

In early December, US Secretary of State John Kerry told the Senate Foreign Relations Committee that any congressional authorization of military force against Islamic State militants should not prohibit the use of ground troops or limit the battles in Iraq and Syria.

READ MORE: Kerry to Congress: Don’t limit ISIS war or block ground troops