Gazprom CEO Alexei Miller said that Moscow will play by its own rules after cutting daily gas supplies to Germany and Italy.

"Our product, our rules. We don't play by rules we didn't create," Miller said during a panel discussion at the Saint Petersburg International Economic Forum in Russia's second city.

Earlier this week, Gazprom slashed its natural gas deliveries via the Nord Stream pipeline, after saying Germany's Siemens had delayed the repair work of compressor units at the Portovaya compression station.

"For now, there is no way to solve the problem that arose with the compressor station," Miller said.

"Siemens is still silent, trying to find a solution."

Italian energy giant Eni also reported problems, saying it will receive only 65 percent of the gas requested Thursday from Gazprom.

Gazprom has said exports to countries that did not belong to the former Soviet Union were down 28.9 percent between January 1 and June 15 compared to the same period last year.

"Of course, Gazprom is reducing the volume of gas supplies to Europe," Miller said, pointing out that the prices have increased several-fold.

"If I say we are not offended by anyone, then I am not pretending," Miller said.

Gas prices continued to soar on Thursday, galvanized by a sharp cut in supply from Russia. Europe's reference natural gas price, Dutch TTF, reached almost 150 euros ($158) per megawatt/hour before falling to 134 euros in the afternoon.

Moscow has lost several European gas clients after it demanded that all "unfriendly" countries pay for Russian natural gas in rubles in response to a barrage of Western sanctions over Russia's military intervention in Ukraine.

Poland, Bulgaria, Finland and the Netherlands have had their natural gas deliveries suspended over refusing to pay in rubles.

The Nord Stream pipeline was commissioned in 2012 and delivers gas from northwestern Russia to Germany via the Baltic Sea.

The launch of the Nord Stream 2 pipeline that was set to double Russian gas deliveries to Germany was halted in response to Moscow's military campaign in Ukraine.

"Nord Stream 2 is under pressure and gas could be supplied to Germany even today via it. But it has not been put in operation because it is not certified," Miller said.

EU countries have scrambled to reduce their dependency on Russian energy but are divided about imposing a natural gas embargo as several member states are heavily reliant on Moscow's energy supplies.