MOSCOW - Russia is suspending the flow of gas supplies through the crucial Nord Stream 1 pipeline indefinitely, raising fears of an energy shortage in Europe as the cold winter months approach.

The Russian state-controlled energy giant Gazprom claimed on September 2 that deliveries to Germany could not be restarted after a three-day maintenance pause because a new oil leak had been discovered.

Gazprom said the oil leak was discovered at the Portovaya compressor station on the Russian end of the pipeline and that deliveries could not safely be restarted until the problem is resolved.

The Nord Stream 1 pipeline under the Baltic Sea had been scheduled to resume operations on September 2 after a three-day pause for maintenance.

The stoppage has fueled fears that Russia will keep the pipeline offline for a longer period to put pressure on Western nations and break their unity in sanctioning Russia for its war against Ukraine.

Moscow has repeatedly denied it uses energy supplies as a weapon.

Germany-based Siemens Energy, which services Nord Stream 1 turbines, said a leak of this nature should not force the pipeline to halt operations.

Siemens also said the Portovaya compressor station has other turbines for Nord Stream to keep operating.

"Such leaks do not normally affect the operation of a turbine and can be sealed on site. It is a routine procedure within the scope of maintenance work," the company said.

Earlier in the day, former Russian President Dmitry Medvedev warned the European Union that Moscow could halt the flow of natural gas to the bloc if it introduces a price cap on Russian supplies as urged by European Commission chief Ursula von der Leyen.

Von der Leyen on September 2 called for a price cap on Russian pipeline gas to prevent Moscow from manipulating the EU's energy market in retaliation for sanctions sparked by the Kremlin's invasion of Ukraine in late February.

In response, Medvedev, who has taken a hard line against countries that have slapped sanctions on Russia over the invasion, said a cap would trigger a response and "there will simply be no Russian gas in Europe."

Last month, the pipeline was shut for 10 days of maintenance, but the new halt in supplies was announced less than two weeks in advance and is being carried out by Gazprom rather than the operator of Nord Stream 1.

Moscow slashed supplies via the pipeline to 40 percent of capacity in June and to 20 percent in July, claiming maintenance issues and sanctions that it says prevent the return and installation of equipment.

The disruption and reduction in supplies has sent gas prices soaring and forced European governments to scramble for alternative supplies ahead of the winter.

Separately on September 2, the Group of Seven (G7) said following a summit in Germany that it was moving forward on instituting a price cap on the export of Russian oil products. No time frame was set for the move to take place.

EU countries are to discuss imposing a gas-price cap, as strained markets reopen this week to news that Russia's pipeline to Germany will stay shut.

Energy ministers meeting in Brussels on Friday (9 September) will consider caps on imported gas and on gas used for electricity production, according to a Czech EU presidency document seen by Reuters.