The US military on Tuesday backed up Turkey's claim 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 added it was not immediately clear on which side of the Turkish-Syrian border the Russian jet had been flying; Turkey claims the jet breached its airspace, while Russia argues it was flying over Syria.