Any decision to stop energy imports from Russia in retaliation for Moscow’s invasion of Ukraine will affect France’s and Europe’s energy supply next winter, Engie CEO Catherine MacGregor warned on Monday.

“Winter is coming to an end. The real problem will be next winter as we replenish our stocks over the summer,” MacGregor told France Inter radio, according to Reuters.

US Secretary of State Antony Blinken has said Washington and European allies are discussing a possible embargo on Russian oil imports with a view to tightening economic sanctions on Moscow. German Finance Minister Christian Lindner has spoken out against a ban on imports of gas, oil and coal from Russia as part of new sanctions on the invasion of Ukraine. Germany is more dependent on natural gas imports from Russia than many other neighboring countries.

The price of natural gas reached a new all-time high on the European market on Monday morning, while the price of a barrel of crude oil exceeded $139 on the London Stock Exchange, according to Agerpres.

At the TTF gas hub in the Netherlands, where reference prices are set in Europe, prices rose 79% on Monday to a new record of 345 euros per Megawatt-hour. Monday’s advance is a continuation of an appreciation trend that has doubled prices over the past week after Russia’s invasion of Ukraine and international sanctions on Russia have upset commodity markets around the world.