EU countries have increasingly relied on US energy imports, though shale bosses warned the ability to boost oil and gas supplies would be challenging. 

"It's not like the US can pump a bunch more. Our production is what it is," Wil VanLoh, head of private equity group Quantum Energy Partners, one of the shale's most prominent investors, told Financial Times. 

"There's no bailout coming," VanLoh added. 

"Not on the oil side, not on the gas side.

Europe can thank the Democrats and the Biden administration for their war against crushing the US energy industry that led to massive divestments across the sector, which crippled oil production growth and refining capacity, and pressured/shamed the world into withdrawing any capital allocations to fossil fuels.

Ben Dell, chief executive of private equity group Kimmeridge Energy, said the shale industry's investors on Wall Street would not give their blessing to a big production increase, preferring a low-production, high-profit model.

"Investors generally don't want shale companies to pursue a growth model," he said.

"The capital availability is extremely limited."