The parties discussed Russian-Ukrainian cooperation in the gas sector, including the settling of mutual claims related to the execution of contracts, the terms of transiting Russian gas to Europe from 2020 onward, and the outlook for direct purchases of Russian gas for Ukrainian consumers.

"Мы высоко ценим тот высокий уровень взаимоотношений, который сложился между Россией и Ираном. Мы последовательно реализуем курс лидеров наших стран по наращиванию взаимодействия, нацеленного на укрепление двустороннего сотрудничества", - подчеркнул глава Минэнерго России.

Last week, President Vladimir Putin said Russia wanted to resume direct gas sales to Ukraine -- and would be prepared to reduce the price Kyiv paid by 20%-25%.

The potential delay in Nord Stream 2 construction also undermines Russia's position in negotiating a new transit deal with Ukraine's Naftogaz. Ukraine transited some 87 Bcm of Russian gas to Europe in 2018 -- or some 44% of total Russian exports -- but those volumes are set to slump once the planned Nord Stream 2 and TurkStream gas pipelines come online.

Россию и Белоруссию связывают многолетние, прочные отношения в сфере энергетики, между странами постоянно ведется важная совместная работа по ряду проектов и инициатив, отметил Александр Новак по итогам переговоров.

In a statement, Gazprom said it had sent a letter to Naftogaz -- signed by Gazprom CEO Alexei Miller -- to "extend the existing contract or to conclude a new gas transit agreement through Ukraine for a period of one year."

Poland is seeking a foreign investor for a 49% stake in the company that will be responsible for building and operating six reactors, Piotr Naimski, a top government official in charge of strategic energy infrastructure, said

If the key reforms move forward expeditiously, Ukraine's economic growth is projected at 3.6 percent in 2019, 3.7 percent in 2020, and 4.2 percent in 2021.

Putin said Ukraine still had work to do to align its gas regulatory landscape with that of Europe, questioning whether Kiev would be able to achieve this in time. "That is not up to us," he said. "Therefore, the risk of termination of transit exists."

Brent was down 43 cents at $61.85 a barrel , WTI slipped 22 cents to $56.55 a barrel.

"The law implements a European compromise, in which we, together with France and the Commission and other member states played a major role," Altmaier said.

The timeline for work to lay the section of pipeline in Danish waters will be key to when Nord Stream 2 is able to begin flowing gas, with wider implications for the European gas market -- including whether Russia's Gazprom agrees a new transit deal with Ukraine's Naftogaz.

Poland's antitrust authority, the Office of Competition and Consumer Protection (UOKiK), said Friday it had imposed a fine on France's Engie of Zloty 172 million ($44.5 million) for its failure to provide the watchdog with documents regarding its agreements with Gazprom aboutfinancing the Nord Stream 2 gas pipeline.

Alexey Miller pointed out that a number of strategic issues need to be resolved prior to the signing of a new transit contract.

Poland sees Nord Stream 2, which would double Russia’s gas export capacity via the Baltic Sea, as a threat to Europe’s energy security and argues it will strengthen Gazprom’s already dominant position on the market.