Ukraine had complied with all recommendations by the International Civil Aviation Organization (ICAO) regarding air traffic control in Ukraine's airspace and restrictions on flights through it at the time of the Malaysia Airlines Flight 17 (MH17) crash on July 17, 2014, Ukrainian Deputy Prime Minister and head of the ad hoc governmental commission investigating the crash Hennadiy Zubko said.

"All ICAO recommendations were met," Zubko said at a press conference in Kyiv on Tuesday.

Ukraine had gradually closed flight levels up to 9,750 meters in its airspace, Zubko said.

Zubko insisted on working together to prove that ICAO recommendations need to be adjusted and said that Ukraine had met all "possible and impossible" requirements unilaterally to prevent such disasters.

The Dutch Safety Board concluded in its report published on Tuesday that there had been sufficient reasons to close airspace over the eastern part of Ukraine where MH17 was downed.