ST. PETERSBURG, June 16. /TASS/. Reduction of oil supplies to Belarus was due to underpayment, Deputy Prime Minister Arkady Dvorkovich told journalists on Thursday.

"Our Belarusian friends, unfortunately, underpay for gas, which affects the budget, because Gazprom is a large taxpayer, Of course, we have to seek compensation," he said.

Earlier on Thursday, Energy Minister Alexander Novak said on the sidelines of the St. Petersburg International Economic Forum said that Russia’s oil supplies to Belarus may be slightly cut in the third quarter of this year.

"The current schedule implies a slight decrease (of oil supplies to Belarus - TASS) compared with initial plans," Novak said, adding that this is related to the capacity of the gas and oil transmission system.

In Minsk, such intentions later were called illegal, and Novak's statements "unfounded."

Gazprom Deputy CEO Alexander Medvedev said earlier that the debt of Belarus for Russia’s gas supplies exceeds $200 mln.

"There are arrears in payment to the Belarusian company (Gazprom Transgaz Belarus owned by Gazprom - TASS) from Belarus’ consumers. The backlog is rather serious, exceeding 200 (mln dollars)," he said.

In early May, Gazprom Transgaz Belarus filed a lawsuit to the International Arbitration Court at the BelCCI (Belarusian Chamber of Commerce and Industry) against the country’s gas providers over their debts on Russia’s gas supplies.

Last year the price of Russian gas for Belarus stood at $142.4 per 1,000 cubic meters. Meanwhile Minsk said there were reasons for reducing the price for gas in 2016. In January, Deputy Prime Minister Arkady Dvorkovich and his Belarusian counterpart Vladimir Semashko held talks but failed to agree on a gas price discount.

Five mln tonnes for six months

Head of Transneft Nikolay Tokarev said Russia is going to reduce oil supplies to Belarus by 5 mln tonnes for remaining six months.

"In my opinion, 5 million tonnes for the remaining two quarters," Tokarev said.

Head of Transneft said the Belarusian side should fulfill its obligations on returning oil products to Russia in agreed volumes, which that do not do.

"Naturally, we often have shortfall in revenue for the Russian side, and it needs to be compensated by something. In particular, by reducing oil supplies. There is also the gas issue, but there are different problems, I think these questions are somehow related," Tokarev said.