Medvedev, who is on a trip to Europe, said in an interview with Luxemburger Wort newspaper, published late on Monday, that Russia can use Ukraine for gas transit in the future "under certain conditions."

"I underline this particularly: we don't reject transit through existing pipelines... We are ready to maintain gas transit through Ukrainian pipelines after 2019," he was quoted as saying.

"Of course, under certain conditions ... They are a settlement between interested companies, favourable economic and commercial parameters of the deal as well as a stable political situation," Medvedev said.

Russia’s planned doubling of capacity on the Nord Stream pipeline across the Baltic Sea to Germany could help Moscow bypass exports via Ukraine. That would deny Kiev transit fees.

Russia is involved in a conflict with Kiev over the annexation of Crimea and breakaway regions in Ukraine’s east.

(Reporting by Vladimir Soldatkin, writing by Maria Tsvetkova. Editing by Jane Merriman)