Britain's possible leave of the European Union (EU) could complicate the introduction of Single Sky between Ukraine and the EU due to a dispute over the Gibraltar airport, Ukrainian Infrastructure Minister Volodymyr Omelyan has said.

"We will see what the final decision after the referendum in Britain will be. Today's statement of David Cameron that the new government should hold new talks is not the best option. We have the position of Spain which considers Gibraltar its territory. I would say that this slightly complicates the situation," he told reporters before a government meeting on Friday.

The minister added that the Single Sky with the EU is being negotiated. Each meeting with EU representatives starts with the issue of Single Sky.

"They understand that the ball is in their court," he said.

Ukraine and the EU have several times postponed the signing of Single Sky agreement. The official reason of the delay is a lack of agreement of the Spain and Britain's position over the territorial use of the Gibraltar airport.