Russia on Thursday restored critical gas supplies to Europe through Germany via the Nord Stream pipeline after 10 days of maintenance, but uncertainty lingered over whether the Kremlin would still trigger an energy crisis on the continent this winter.
Germany, which is heavily dependent on Russian gas, had feared that Moscow would not reopen the pipeline after the scheduled work and accused Moscow of using energy as a "weapon".
The showdown came amid the worst tensions in several years over Russia's invasion of Ukraine. Germany believes Russia is squeezing supplies in retaliation for Western sanctions over the war.
Klaus Mueller, head of Germany's energy regulator, the Federal Network Agency, said that by late morning gas flows were on track to return to 40 percent of the pipeline's capacity -- the same reduced level as before the maintenance work.
"But given the missing 60 percent (of supply) and political instability, there is no reason to sound the all-clear," he tweeted.
Enduring German reliance on Russian gas coupled with alarming signals from Moscow have turned up the pressure on Europe's top economy.
A total shutdown of imports or a sharp reduction in the flow from east to west could have a catastrophic effect, shutting factories and forcing households to turn down the heat.
Even the resumption of 40 percent of supplies would be insufficient to ward off energy shortages in Europe this winter, experts warned.
The International Monetary Fund said on Wednesday that a halt in supplies could slash Germany's gross domestic product this year by 1.5 percent.
- 'Will fulfil' -
Russia's state-owned energy giant Gazprom cut flows to Germany via the Nord Stream 1 pipeline under the Baltic Sea to some 40 percent of capacity in recent weeks, blaming the absence of a Siemens gas turbine that was undergoing repairs in Canada.
The turbine is reportedly en route to Russia and expected to arrive on Sunday at the earliest. The German government has rejected Gazprom's explanation as an "excuse", noting that the turbine was one of several available.
Moscow's explanation for the supply shortfall shifted again on Thursday, as it said that gas delivery problems to Europe were caused by Western sanctions.
"Any technical difficulties linked to this are caused by those restrictions that European countries introduced themselves," Kremlin spokesman Dmitry Peskov told reporters.
Russian President Vladimir Putin insisted this week that Gazprom would meet all its delivery obligations.
"Gazprom has fulfilled, is fulfilling and will fulfil its obligations in full," Putin told reporters in Tehran after holding talks with the leaders of Iran and Turkey.
He warned, however, that as another gas turbine was due to be sent for maintenance at the end of this month, energy flows could fall to 20 percent of capacity from next week.
- 'Blackmail' -
As of Wednesday, German gas reserves were about 65 percent according to official estimates. The reduced supply has prevented EU countries from replenishing holdings before winter.
The European Commission on Wednesday urged EU countries to reduce their demand for natural gas by 15 percent over the coming winter months, and to give it special powers to force through needed demand cuts if Russia severs the gas lifeline.
"Russia is blackmailing us," Commission president Ursula von der Leyen, a former German defence minister, told reporters.
"Russia is using energy as a weapon and therefore, in any event, whether it's a partial major cut-off of Russian gas or total cut-off... Europe needs to be ready."
Peskov at the Kremlin said on Thursday that the blackmail accusations were "completely" unfounded.
German Economy Minister Robert Habeck, who has said he is taking shorter showers to save energy, stressed that industry -- but also consumers -- would have to do their part to reduce Russia's power in the current standoff.
"A decisive bit of leverage is reducing gas use," he said. "We have to do everything in our power to work on that."