Europe needs to prepare “immediately” for Russia to turn off all gas exports to the region this winter, according to the head of the International Energy Agency, who has called on governments to work on reducing demand and keeping nuclear power plants open.

Fatih Birol said that the reductions in supplies in recent weeks the Kremlin has attributed to maintenance work could, in fact, be the beginning of wider cuts designed to prevent the filling of storage facilities in preparation for winter, as Russia seeks to gain leverage over the region, The Guardian reported.

“Europe should be ready in case Russian gas is completely cut off,” he said in an interview with the Financial Times. “The nearer we are coming to winter, the more we understand Russia’s intentions.”

“I believe the cuts are geared towards avoiding Europe filling storage, and increasing Russia’s leverage in the winter months.”

EU countries are racing to refill storage sites, with Germany hoping to reach 90 per cent of capacity by November. Its stores are only half full, The Guardian reported.

Member states have also been working to reduce their reliance on Russian fossil fuels, by sourcing gas from other countries, including the US, and by speeding up the switch to renewable energy, although officials have conceded that the race to phase out Russian oil and gas would mean burning more coal and keeping nuclear plants going.

Birol said emergency measures taken by European governments to reduce energy demand had probably not gone far enough, and urged countries to work on preserving energy supplies.

“I believe there will be more and deeper demand measures as winter approaches,” Birol said. He added that gas supplies may need to be rationed, if Russia were to further reduce gas exports.

Moscow has reduced or even cut off gas deliveries to several EU countries in recent weeks, in response to their decision to impose sanctions on the Kremlin over its invasion of Ukraine.

Russian gas supplies to Europe received through the Nord Stream 1 pipeline – which runs under the Baltic Sea to Germany – have been falling, The Guardian reported.