President Volodymyr Zelensky pushed back against pressure from the U.S. to stop attacking Russian oil refineries, writing on social media on Oct. 11 that Moscow first needs to stop targeting Ukraine's energy infrastructure.

"The real cause of the war in Europe is Russia, and Russia alone. It is already possible today to halt the attacks on our energy sector, but (Vladimir) Putin does not want to do so," Zelensky said.