A US Army veteran who served in three combat tours of the Middle East is locked in a desperate battle to gain asylum for his Iraqi comrade before he is killed by ISIS.

When Chase Millsap, 33, was on routine patrol in Iraq, his life was saved by a native soldier who threw him to the floor as sniper fire whizzed over his head.

But now the former officer, known only as The Captain, is living a precarious existence as a refugee, dodging ISIS militants who want to kill him because he worked with the Americans.

For the past two years Millsap has been fighting to gain asylum for his brother in arms, unable to leave his comrade behind.