President Donald Trump says his administration has already had “very serious” discussions with Russia about its war in Ukraine and that he and Russian President Vladimir Putin could soon take “significant” action toward ending the grinding conflict.

Russia’s ability to keep making fuel at the normal pace is looking increasingly precarious following a surge in Ukrainian drone attacks on the nation’s oil refineries, including a fresh incident on Friday.

"This refinery is one of the 10 largest oil refineries in Russia in terms of design capacity and is involved in supplying the Russian occupatying army," the General Staff said in a statement.