Kremlin-controlled energy company Gazprom PJSC said it would suspend the Nord Stream natural-gas pipeline to Germany until further notice, raising the pressure on Europe as governments race to avoid energy shortages this winter.

Gazprom said Friday that it found a technical fault during maintenance of the pipeline, which connects Russia with Germany under the Baltic Sea. The company said the pipeline would remain shut down until the issue is fixed, without giving any timeline.

The pipeline was due to resume work early Saturday after three-day maintenance. Before the maintenance, the pipeline was operating at 20% of its capacity.

Russia first began throttling supplies via Nord Stream in June, saying that needed maintenance was being prevented by Western sanctions imposed following Russia’s invasion of Ukraine. The notion was dismissed by European officials as an excuse for Russian President Vladimir Putin’s regime to use its gas exports to punish Europe for its support of Ukraine.

A complete shutdown of Nord Stream will compel European governments to accelerate their push to become independent of Russian gas ahead of the winter months and could force them to ration energy—a move that would hurt industrial companies and tip the continent’s already fragile economy into a recession.

At the same time, the move deprives Moscow of its most potent economic leverage on the continent and could remove any remaining misgivings in European capitals about raising sanctions on Moscow for fear of retribution.

“Until it is repaired. gas transport via Nord Stream is completely stopped,” Gazprom said Friday.

Moscow and the West have been engaged in an economic war since Russia invaded Ukraine in February. Western democracies have inflicted economic and financial sanctions on Russia, and Moscow has tried to choke unfriendly countries’ access to its natural gas, which Europe uses for heating and electricity production.

German Finance Minister Christian Lindner on Friday said he backed a call by Group of Seven finance ministers to impose a cap on the price of Russian oil in an effort to push down oil prices and deprive Russia of one of its biggest sources of revenues.

Russia would have enough capacity via other gas pipelines to Europe to compensate for the Nord Stream shortfall. However, flows via these other routes declined following the Ukraine war.

Ukraine halted one gas-transit route in May, blaming interference by Russian forces. Deliveries through another, called Yamal, which traditionally transported gas from Russia to Europe, have stopped this year due to sanctions imposed by Russia on the Polish part-owner.

Germany’s economy minister Robert Habeck said this week that the country can’t count on Nord Stream during the winter.

In reaction to Russia’s Nord Stream decision, Klaus Müller, head of Germany’s energy regulator, said the country would need to boost gas imports from other suppliers, continue to fill up gas stores and cut gas consumption.

European officials had expected that the Kremlin would use gas flows to keep markets and governments on edge and erode support for Ukraine among Western voters.

Natural-gas prices have broken records in recent weeks amid the energy crunch, though they have also dropped sharply in the past days, with some analysts crediting the speed at which Europeans have been filling up their gas storage facilities through the summer.

Gazprom began throttling gas flows in June, citing technical problems with the turbines. The company insists that a key turbine couldn’t be sent to Russia after it was maintained in Canada because of international sanctions on Moscow. But Germany, where the turbine was located, said that there are no obstacles and that Moscow was in fact blocking the turbine’s return to Russia.

On Friday, Gazprom said that it found an oil leak in a turbine at the compressor station of the pipeline. Gazprom said that similar issues had been found with other turbines this summer which have led to the reduction of the gas flows.

Gazprom said it had notified the manufacturer of the turbine, German company Siemens Energy AG , of the new leak. Gazprom said that the necessary repairs could only be done in “the conditions of a specialized repair workshop.”

Siemens Energy didn’t immediately respond to a request for comment.

Europe has been preparing for a possible Russian gas cutoff, with EU gas- storage facilities filling up faster than expected this summer, to over 80%.

Still, if Nord Stream remains shut, Europe’s gas stores would end the winter at 26% of their capacity, which would complicate Europe’s situation next winter, Massimo Di Odoardo, vice president for gas and liquefied natural gas research at energy consulting firm Wood Mackenzie, wrote this week.

Germany, which received more than half of its gas from Russia before the war in Ukraine, has been racing to diversify its supply of gas and to install floating liquefied natural gas terminals to ship in gas from the U.S. and elsewhere.

The country is close to hitting its 85% gas storage target, initially set for Oct. 1. German officials, however, have warned that reaching the next milestone of 95% by Nov. 1 would be challenging unless companies and households cut consumption.

The 760-mile-long Nord Stream pipeline first opened in 2011. Russia and a consortium of European energy companies built a second pipeline, Nord Stream 2, running alongside the original one, that would have doubled capacity. But the German government froze the project in February over the war in Ukraine.

Write to Georgi Kantchev at georgi.kantchev@wsj.com