Ukraine today stepped up its economic warfare with Russia by demanding a mult-billion-dollar payment from the Gazprom gas giant for allegedly underpaying Kiev for its fuel transits to European states.
The gesture is largely symbolic because Russia has dismissed similar Ukrainian claims.
But it underscores the severe tensions between the two neighbours and potentially complicates the solution of a litany of existing trade disputes.
The westward-leaning former Soviet country's Anti-Monopoly Committee said Gazprom had two months to pay USD 3.5 billion for abusing the "monopoly status" it enjoys on gas transits through Ukraine.
The committee's deputy chief Mariya Nyzhnyk said the sum represented 30 per cent of the price for natural gas that passed through the country over the past five years.
The Russian firm expressed "extreme surprise" at the announcement and stressed that it would have no impact on its future operations in Ukraine.
"Gazprom intends to defends its rights and legitimate interests by all legal means at its disposal," it said in a statement.
Ukraine's decades-old pipelines account for about 15 per cent of all gas imported by the European Union -- its members rely on Russia for about a third if their outside supplies.
Some of Gazprom's EU clients saw their deliveries limited in 2006 and 2010 when the state-run behemoth - long accused of raising the rates of neighbours who want to ease their dependence on Moscow - halted supplies to Ukraine over price disputes.
Kiev's announcement came just three days after Gazprom itself demanded the payment of a previously-undisclosed USD 2.55 billion bill for the July to September period of 2015.
Ukraine has been weening itself off Russian energy imports and purchased almost no gas from its eastern neighbour in the period mentioned by Gazprom.
But the Russian firm said the amount it was after fell under the take-or-pay scheme that requires clients to reimburse Gazprom for any contracted gas they failed to purchase in a specific timeframe.
Russia's latest charge brings to nearly USD 32 billion the bill it claims is due by Kiev.
Ukraine's Naftogaz state energy company is itself seeking nearly USD 26 billion from Gazprom in a Stockholm arbitration court.
Kiev authorities have vowed repeatedly not to halt shipments to Europe despite its multiplying disputes with Gazprom.
