Ukrainian aviation authorities also have declared some airspace in the east to be “danger areas” because of attempts by Russian aviation authorities to seize control of the airspace.
Ukraine acted after Russia issued a ban on civilian air traffic in airspace over eastern Ukraine.
The announcement on Wednesday night (local time) establishes buffer zones for traffic controlled by Ukrainian authorities to avoid coming into potentially hazardous conflict with air traffic controlled by Russian authorities.
Last week, Ukrainian aviation officials warned pilots in the region to be on the lookout for Russian authorities trying to take control of the airspace and to only recognise Ukraine’s controllers.
Russia had earlier issued a notice banning civil aircraft from flight routes bordering north-eastern Ukraine.
Russia issued a NOTAM (notice to airmen or notice to air missions) that covers a corridor of territory where Russian forces have gathered over the past weeks.
The NOTAM remains in force until May 18.
Travel expert Quentin Long, of Australian Traveller Magazine, told Today the escalating Ukraine crisis could force airlines to re-route and airlines would be monitoring the situation.
He said there is a major flight path through Ukraine, flown by commercial aircraft from Europe to south-east Asia.
“As long as things don’t escalate, we will just fly around them and be OK. And then we will watch and wait and see what happens,” Mr Long said.