The United States and the European Union pledged on Monday to work to ensure gas supplies can respond to disruptions in pipeline gas flows, as tensions rise over the massing of troops on Ukraine’s borders by Russia, Europe’s biggest gas supplier.

“We’re working together right now to protect Europe’s energy supply against supply shocks, including those that could result from further Russian aggression against Ukraine,” U.S. Secretary of State Antony Blinken told reporters in Washington, alongside Josep Borrell, the EU foreign policy chief.

Europe’s dependence on Russian gas has come under scrutiny in recent months as lower than expected supply from Russia and rising tensions over Moscow’s build-up of more than 100,000 troops on its borders with Ukraine have helped to push prices to record highs.

Russia provides about 40 per cent of Europe’s natural gas.

Blinken said the coordination with allies and partners includes “how best to share energy reserves in the event that Russia turns off the spigot, or initiates a conflict that disrupts the flow of gas through Ukraine”.

Borrell said the immediate priority is to diversify sources of energy and gas flows to avoid supply disruption and “ensure that the world energy markets will be liquid, competitive and well supplied”.

The officials spoke earlier at an EU-U.S. Energy Council meeting.

A joint statement of the council said the EU and the United States intended to work together so global liquefied natural gas (LNG) markets can provide “additional and diversified supplies in case of pipeline gas disruptions in the short term as countries move away from fossil fuels and towards a sustainable net-zero future”.

Lower than usual gas supplies from Russia in recent months have prompted EU officials and the International Energy Agency to accuse Moscow of contributing to an under-supply to Europe.

“It is unacceptable to use energy supply as a weapon or geopolitical lever,” the EU-U.S. statement said.

Gazprom has said it is fulfilling all long-term contracts, and the Kremlin says it is not planning an invasion.

Europe’s LNG imports hit a record high in January at 11.8 bcm, with nearly 45% coming from the United States.

As it reviews its contingency plans for gas supply disruptions, EU officials have been in talks since late last year with suppliers including Qatar and Norway.

Initially, the talks were primarily a response to high prices, but the heightened tensions with Russia have intensified the discussions.

“There was a clear willingness from Azerbaijan to support the EU in case of a disruption of gas flows,” EU energy policy chief Kadri Simson said after meeting government officials in Azerbaijan last week.

Unused LNG infrastructure capacity in Europe could handle bigger volumes, although analysts warn of bottlenecks including limited global liquefaction capacity.

The joint statement made clear gas could only be a short-term solution, citing the longer term need to move away from fossil fuels, such as gas, as the EU seeks to limit global warming and achieve net zero emissions by 2050.