"Airspace users [airline operators] have the ultimate responsibility to decide where they are able to operate safely," Anthony Philbin told the news agency.
The communications chief noted that countries still "continue to have the responsibility to ensure the safety of civil aviation operations in their sovereign and delegated airspace."
The Malaysia Airlines, crashed plane's operator, followed the instruction of the Ukrainian authorities, turning a blind eye, however, to the fact that the route was laid over a combat zone.
Earlier on Friday, the European Organisation for the Safety of Air Navigation (Eurocontrol) told Sputnik that the decision to leave the airspace open over eastern Ukraine was solely of Kiev.
All 298 people on board of the fatal flight lost their lives. Kiev and local independence supporters have been trading the blame for the tragedy.
