STORY: Gazprom has told European customers it can't guarantee gas supplies - because of 'extraordinary' circumstances.
That's according to a letter from the Russian energy company - viewed by Reuters - in which it said it was declaring a force majeure on supplies starting June 14th.
The letter itself was dated July 14th - and addressed to at least one major customer.
Known as an 'act of God' clause, force majeure is used to shield a business from factors beyond its control - like natural disasters.
Gazprom had no immediate comment.
It marks an escalation in an economic tit-for-tat with the West over Moscow's invasion of Ukraine.
Uniper - Germany's biggest importer of Russian gas - was among the customers who said they had received the letter and that it had formally rejected the claim as unjustified.
A source tells Reuters the force majeure concerns supplies through the Nord Stream 1 pipeline - a major supply route to Germany and beyond.
It's currently undergoing maintenance - and Europe fears Moscow could keep the pipeline mothballed in retaliation over sanctions heightening an energy crisis that risks tipping the region in recession.
The European Union aims to stop using Russian fossil fuels by 2027 - but wants supplies to continue for now as it develops alternative sources.