Alexander Lukashenko has threatened to cut the transit of gas and goods through Belarus to Europe if the EU imposes further sanctions on his regime over the migrant crisis on the Belarusian-Polish border.

The Belarus president was responding to an announcement by Ursula von der Leyen, European Commission president, on Wednesday that the bloc would widen its sanctions on Lukashenko’s regime, accusing Minsk of a “cynical geopolitical powerplay” in funnelling migrants to the EU’s borders in an attempt to destabilize it.

On Thursday Lukashenko warned Minsk would respond to any “unacceptable” sanctions.

“We are heating Europe, and they are threatening to close the border,” he said, according to Belarus state news agency Belta. “What if we cut off gas to them? Therefore I recommend that the leaders of Poland, Lithuania and the other headless people think before speaking. We should not stop at anything to defend our sovereignty and independence. ”

European gas prices have soared this year amid concerns over low supplies ahead of winter. Global availability has tightened as economies rebound from the Covid-19 pandemic, with Europe competing with Asia for shipments of liquefied natural gas from suppliers such as the US, Qatar and Australia, while pipeline shipments to western Europe from Russia have been lower than usual.

Prices eased this week amid signs that Russia’s state-backed gas giant Gazprom was beginning to refill its storage facilities in Europe. But they rose on

Thursday, with the European benchmark gaining more than 5 percent to €75.25 per megawatt-hour.

As much as 40 percent of the EU’s gas comes from Russia, with about a fifth passing through Belarus in 2020, according to analysts. But EU lawmakers have accused Moscow of withholding supplies to the bloc in an attempt to speed up approval of the controversial new Nord Stream 2 pipeline through the

Thierry Bros, a former oil and gas adviser at the French economy ministry and a professor at Sciences PO in Paris, said Russia and Gazprom would ultimately determine whether Lukashenko carried out his threat.