Ukrainian forces have pulled back from the airport in the eastern city of Luhansk following clashes with pro-Russian separatists.
Ukrainian National Security and Defense Council (NSDC) information and analytical center spokesman Andriy Lysenko said this at a briefing in Kyiv on Monday.
The announcement comes as Russian Foreign Minister Sergei Lavrov expressed hope participants at a meeting in Minsk on September 1 would agree terms of an immediate, unconditional cease-fire.
The rebels have been fighting Ukrainian government forces since April in a conflict the United Nations says has killed more than 2,600 people.
East Ukrainian cities of Luhansk and Donetsk are the main strongholds of separatists.
Ukraine and the West accuse Russia of sending troops into Ukraine and supporting the separatists, allegations denied by Moscow.