President Volodymyr Zelensky on Wednesday made another in a series of battlefield visits, meeting with soldiers and officers in the eastern Donetsk region, stopping by a hospital to see wounded troops and giving state awards to the defenders of Bakhmut, a devastated city that has become a symbol of Ukraine’s dogged resistance under a threat of Russian encirclement and for months has been the scene of the war’s bloodiest fighting and longest battle. Zelensky’s last known visit to the Bakhmut area was in December.