Ukraine’s military has said it struck a major oil terminal in occupied Crimea that provides fuel for Russia’s war effort as Ukrainian President Volodymyr Zelenskyy said the war has entered a key phase.

“At night, a successful strike was carried out on the enemy’s offshore oil terminal in temporarily occupied Feodosia, Crimea,” the Ukrainian military said in a post on social media on Monday.

Both Moscow and Kyiv are facing the issue of how to sustain their costly war of attrition – a war that started with Russia’s full-scale invasion of Ukraine in February 2022 – that shows no signs of a resolution.