The US military on Tuesday backed up Turkey's earlier assertion that Turkish pilots had warned a Russian jet 10 times -- but failed to get a response -- before shooting it down."We were able to hear everything that was going on, these (communications) were on open channels," military spokesman Colonel Steve Warren said.Asked if he could confirm reports 10 warnings were issued by Turkish pilots without response, Warren said: "I can confirm that, yes."He said it was not immediately clear on which side of the Turkish-Syrian border the Russian jet had been flying.Warren, speaking via video conference from Baghdad, also said he could not confirm the status of the downed Russian pilots.The Russian warplane violated Turkish air space despite being warned 10 times in the space of five minutes, the Turkish military said in an earlier statement.Two Turkish F-16 jets on patrol duty along the border were involved in the downing of the warplane, the military statement added.The military has also released a path analysis [red dotted line] of the downed Russian jet, showing the entry and exist of the plane into Turkish airspace. Moscow, on the other hand, claimed that it could prove the jet had not left Syrian air space.The downing of the warplane was not an action against any specific country but a move to defend Turkey's sovereign territory within the rules of engagement, a senior official told Reuters on Tuesday.