Germany's gas reserves would last until at least late summer should Russian supplies stop now, the network regulator said today.
But it warned that pressure on the European Union to ban Russian energy was building over civilian deaths in Ukraine.
In an interview with weekly Die Zeit, Klaus Mueller, who heads Germany's Bundesnetzagentur, said current reserves looked slightly better than three or four weeks ago and could even last until early autumn in the event of an immediate supply halt.
With mounting civilian deaths in Ukraine amid Russia's invasion, Europe's largest economy is under pressure to wean itself off Russian gas and oil.
Critics say the German revenue provides Moscow with vital funds to wage war.
Mueller told Die Zeit reports of atrocities would increase pressure on the EU to ban Russian gas imports, which would force Germany to ration energy - a prospect he said was underestimated by many Germans.
Russia accuses the US and Britain of helping Ukraine prepare fake claims about the alleged persecution of civilians in the conflict.
Germany last month triggered an emergency plan to manage gas supplies, the first step in a three-phase plan that could result in energy rationing, with priority given to households and critical infrastructure like hospitals.
Mueller said households should not take the promise of prioritisation for granted as they would have to give up some luxuries, such as saunas, if gas is rationed.
He also said large apartments with one tenant should not count on uninterrupted gas supply in an emergency.
He said pharmaceutical and food companies would be prioritised under any rationing.
The EU last week approved new sanctions against Moscow, including a ban on coal imports starting in August, and Germany has stepped up efforts to reduce supplies from Russia.
Russian oil now accounts for 25% of German imports, down from 35% before the February 24 invasion of Ukraine, and gas imports have been cut to 40% from 55%. Russian hard coal imports have been halved to 25%.
Chancellor Olaf Scholz said last week Germany could end Russian oil imports this year. However, Berlin has also said it could take until the summer 2024 to end its reliance on Russian gas.