KYIV, Dec 20 (Reuters) - Ukrainian President Volodymyr Zelenskiy visited troops in the frontline city of Bakhmut on Tuesday and hailed their "superhuman" fighting in one of the main hotspots of the war in Ukraine.Zelenskiy's office released video footage showing the president, dressed in khaki, handing out medals to soldiers fighting in eastern Ukraine.Who with their bravery prove that we will endure and will not give up what’s ours," Zelenskiy said in comments posted on the Telegram messaging app under photographs of him in Bakhmut.Control of the city, with a pre-war population of 70,000-80,000, could give Russia a stepping stone to advance on bigger Ukrainian cities but Ukrainian forces have held on to Bakhmut."The East is holding out because Bakhmut is fighting," Zelenskiy wrote separately in a separate message on Telegram."