The Pentagon is playing down the role of US troops in retaking Iraq's Mosul from ISIS

Thomson Reuters

Fighters from predominantly Sunni Arab force take part in training session before upcoming battle to recapture Mosul in Bashiqa

The Pentagon on Monday played down any new role for US forces in Iraq's battle to retake the city of Mosul from ISIS, saying American personnel were behind the forward line of troops and acting in an advisory role to support Iraqis.

"Americans are again playing an advisor role, an enabler role for these Iraqi forces ... Most of the American forces in Iraq are not anywhere close to the front line," Pentagon spokesman Peter Cook told a news briefing, saying many U.S. troops were on advisory or logistical support missions.

"The role of the US forces today is no different than up to this point."

However, throughout the campaign against ISIS, the US has suffered combat losses on the ground.

Charlie Keating IV, a Navy SEAL, was killed by ISIS fire earlier this year when his quick reaction force responded to a rush of 120 or so ISIS fighters storming mainly Kurdish forces just north of Mosul.

Video of the incident shows US troops out front fighting alongside the Kurdish forces as the battle rages.