The new method of price-formation for natural gas transit through Ukraine, introduced by the Ukrainian national gas regulator since 2016 will increase the tariff on the Russian gas by approximately 50% or even more; talks with Gazprom, however, will be difficult, said Volodymyr Demchyshyn, Ukraine's Minister of Energy and Coal Industry.

"It [the tariff] will be as per the new calculations of the regulator. That is approximately, if I remember, $4.5 per 100 cubic meters. That is around 50% more than previously," he told a press conference in Kyiv on Tuesday.

At the same time he recalled that until recently the tariff had been regulated by bilateral agreements between Naftogaz and Gazprom.