Ukrtransgaz gave no reason for the increase.

More than a third of Russia's gas exports to the European Union cross Ukraine, providing Kiev with valuable income. Russian gas exporter Gazprom has said it wants to bypass Ukraine by building new pipelines.

Russia's gas exports via Ukraine fell 7 percent in 2018 to 86.8 bcm.

Relations between the two countries have deteriorated since Russia annexed the Crimean peninsula in March 2014. Ukraine halted its own imports of Russian gas in 2015.