The US shale industry has warned it cannot rescue Europe with increased oil and gas supplies this winter amid fears that a plunge in Russian exports will send crude prices soaring back above $100 a barrel.

Even though oil markets have softened in recent weeks, the respite could end when an EU embargo on Russian sales comes into full effect later this year. US Treasury secretary Janet Yellen this week warned the embargo “could cause a spike in oil prices”.

However, US shale executives sitting on vast oil and natural gas reserves that could be used to alleviate a European energy crunch say they will be unable to step up supplies quickly enough to prevent winter shortages.

“It’s not like the US can pump a bunch more. Our production is what it is,” said Wil VanLoh, head of private equity group Quantum Energy Partners, one of the shale patch’s biggest investors.

“There’s no bailout coming,” VanLoh added. “Not on the oil side, not on the gas side.”