Vladimir Putin issued a sharp rebuke to his Belarusian counterpart Alexander Lukashenko over the latter’s threat to cut off gas supplies to the European Union.

“He can, I guess, it’s no good, though, and I’ll talk to him about it.” Putin told Russian state media, Politico reported.

Russian gas to Europe runs through pipelines in Belarus and relies on Lukashenko’s cooperation.

“This would be a violation of our transit contract and I hope it will not come to that,” Putin said, adding that if Lukashenko carried out his threat it “would not contribute to the development of our relations with Belarus as a transit country.”

Relations between Belarus and the European Union have deteriorated sharply since Aug 2020 when Lukashenko won elections widely considered fraudulent. Widespread rioting gripped Belarus for months. Sanctions were imposed by the EU shortly thereafter.

European leaders now accuse Lukashenko of allowing migrants from the Middle East to pass through his country to the border of Poland as retaliation. Thousands are now massed there in an attempt to gain entry to the European Union. Aid groups worry the situation could devolve into a humanitarian crisis.