The U.S. is concerned that targeting Russia’s energy facilities will impact the Kremlin’s oil production capacity and drive up global prices — ahead of a knife-edge presidential election where prices at the gas pump are bound to be a contentious topic.

The sources also fear that these repeated strikes will provoke Russia into retaliating and targeting energy infrastructure the West relies on, including oil pipelines.

According to Ukraine’s Deputy Prime Minister for European and Euro-Atlantic Integration Olha Stefanishyna, Ukrainian officials have said that oil refineries are “absolutely legitimate targets from a military point of view.”