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."

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."

"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.

Rosneft already supplies crude to India, shipping to its subsidiary Nayara Energy which operates the 20 million mt/year Vadinar refinery in Gujarat.

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.

Iran started pouring concrete on Sunday at its second nuclear power plant, a key step in building the facility with Russian help in the southern port of Bushehr, state television reported.

China has been relying heavily on Saudi Arabia and Russia for its refinery feedstock requirements over the recent years, with both producers constantly switching between them the top supplier position to Asia's biggest energy consumer.

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.