Ukrainian President Petro Poroshenko said he hopes that the results of Britain's referendum on its exit from the European Union (Brexit) will not influence the further extension of the EU's sanctions imposed on Russia.

"I expect the sanctions against Russia as an aggressor state will be extended," Poroshenko wrote on Facebook on Friday.

Poroshenko said that he believes in further participation of the UK in united Europe and that it will further stand up for common European values.

"I believe that today the top-priority challenge for the EU is to find the way to the hearts of euro-skeptics not to give the opponents of the European integration project and their generous sponsors any chance," he said.

For his part, Ukrainian Foreign Minister Pavlo Klimkin said, commenting on the Brexit referendum results, that "united Europe must overcome the substantial challenges of present and future."

"I believe Ukraine will play an important role in this process," he wrote on Twitter.

"The UK remains a significant friend and partner for Ukraine. These relations are based on common principles and values," he said.

As reported, the referendum's official tally on Friday morning showed that 52% of British voters supported their country's exit from the EU.