President Joe Biden's national security adviser urged energy suppliers on Thursday to lift flows to meet demand, saying that the United States was concerned about their failure to do so.
Rocketing gas prices, with the European benchmark up almost 600% this year, have been fuelled by low inventories and surging demand as economies recover from the COVID-19 crisis.
"The United States has a real concern that, for a variety of reasons, supply is not keeping up with recovering demand," Jake Sullivan told reporters after meetings with the European Union in Brussels, where he discussed the gas issue.
Russia is a major natural gas supplier to Europe, and its energy giant Gazprom is now at the centre of a dispute over whether it could do more to ease prices in the spot market.
Asked if Russia was holding back energy as leverage, Sullivan said: "Russia has a history of using energy as a tool of coercion, as a political weapon."
Russian Deputy Prime Minister Alexander Novak said on Wednesday that certification of the Nord Stream 2 undersea gas pipeline, which is awaiting clearance from a German regulator, could cool soaring European gas prices.
European Commission President Ursula von der Leyen, whom Sullivan met on Thursday, said on Tuesday that Russia was not stepping up natural gas production, unlike Norway.
"We have a fundamental interest in seeing global energy supplies in both gas and oil at sufficient levels to support the global economic recovery and not to stall," Sullivan said.
"We want to see sufficient supply to keep up with recovering demand. And we would like to see energy suppliers take measures to ensure that that is the case," he said.
The United States was engaged in "detailed diplomatic engagement" with energy producers, he added.
