Ukrainian forces have invaded Russian-held areas of northern Donetsk in a move that the UK Ministry of Defense said on Friday was “putting pressure on territory that Russia considers essential to its war aims”. Fighting in northern Donetsk has been described as “ongoing” as Ukrainian forces launch a counter-offensive in the town of Liman, which Russia has captured since May. Lyman is about 30 miles west of Izyum in the northeastern region of Kharkiv, where Ukrainian troops have seen major gains this month recapturing the majority of occupied territory and forcing Russian troops to retreat. Ukraine has announced control of the entire area west of the Oskil River, where territory remains contested from eastern Kharkiv to the Luhansk regions. UKRAINIANS IN KREMLIN-BACKED REPUBLIC VOTE ON WHETHER TO JOIN RUSSIA IN ‘REFERENDUMS’ Armed national guard soldiers walk along a trench in one of the sections of a defense line outside Kharkiv, in Kharkiv region, northeastern Ukraine, in August. (Vyacheslav Madiyevskyy/Ukrinform/Future Publishing via Getty Images) “Russia sought to ‘integrate’ Oskil into a unified defense line following the withdrawal of its forces earlier this month,” the UK Ministry of Defense said on Friday. However, over the past three days, Ukrainian forces have “secured bridgeheads on the east bank” of the dividing river, suggesting they could be in a better position to retake the rest of Kharkiv before advancing on Luhansk. The ministry’s announcement comes as Russia launches referendums in Donetsk, Luhansk, Zaporizhia and Kherson, despite intense fighting in all four regions. BLINKEN SAYS MOSCOW ‘BUSED RUSSIANS’ TO VOTE IN FAKE REFERENDUMS Kharkiv was previously listed as one of the areas Russia intended to annex. Western officials condemned Moscow’s push to illegally seize Ukrainian territory by holding what they called “sham” elections in eastern and southern Ukraine. “Voting” will begin on Friday and polling stations will open on Tuesday. According to Russian state media, RIA, the question on the ballot paper is said to be: “Do you support secession from Ukraine, forming the region as an independent state and joining Russia?” Ukrainian soldiers are seen riding in an armored personnel carrier during an exercise not far from Kharkiv on April 30. (SERGEY BOBOK/AFP via Getty Images) CLICK HERE TO GET THE FOX NEWS APP According to information, the preliminary results will be announced on Tuesday and Wednesday. Ukrainian President Volodymyr Zelenskyy has condemned the election as a “sham” and Western officials have repeatedly pointed to a similar step taken by Russia during its 2014 invasion of Crimea. Caitlin McFall is a reporter for Fox News Digital. She can be reached at [email protected] or @ctlnmcfall on Twitter.