The EU has said leaks in two major gas pipelines from Russia to Europe were caused by sabotage – but stopped short of directly accusing Russia.
Deliberate disruption would result in the “strongest possible response”, said the head of the European Commission, Ursula von der Leyen.
Ukraine earlier went further, accusing Russia of a “terrorist attack”.
The EU has previously accused Russia of using gas supplies, and the Nord Stream line, as a weapon against the West.
But Kremlin spokesman Dmitry Peskov dismissed accusations of sabotage as “predictable, stupid and absurd”.
The US Secretary of State Antony Blinken said he thought the leaks would “not have a significant impact on Europe’s energy resilience”. Neither pipeline is transporting gas at the moment, although they both contain gas.
Mr Blinken did not directly accuse Russia – but said it would be in “no-one’s interest” if they were caused deliberately.
