Service members of Ukrainian Joint Assault Brigade Fury stand next to an S60 cannon near the frontline town of Bakhmut, Donetsk region, Ukraine on December 21, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





A Ukrainian serviceman walks along defense structures near a front line in the Kharkiv Region, Ukraine on December 25, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





Ukrainian servicemen of the 55th Separate Artillery Brigade walk at a position near the front line town of Marinka, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 26, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





A Ukrainian servicemen drives along a frontline in Zaporizhzhia area, Ukraine, 18 December 2023. Russian troops entered Ukrainian territory in February 2022, starting a conflict that has provoked destruction and a humanitarian crisis. (Photo by Yakiv Liashenko/EPA/EFE)





A Ukrainian serviceman of the 55th Separate Artillery Brigade smokes at a position near the front line town of Marinka, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 26, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





Ukrainian service members of the 4th Ivan Vyhovskyi Separate Tank Brigade take their seats in a 2S1 Gvozdika self-propelled howitzer before firing toward Russian troops near the front line town of Kupiansk, amid Russia's attack on Ukraine, on Christmas Eve in Kharkiv region, Ukraine on December 24, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





A Ukrainian serviceman of the Ukrainian 92nd Ivan Sirko Separate Assault Brigade covers his ear during fire from a 2S1 Gvozdika self-propelled howitzer toward Russian troops in a front line near the town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 15, 2023. (Photo by Inna Varenytsia/Reuters)





A Ukrainian serviceman of the 55th Separate Artillery Brigade prepares a M777 howitzer to fire toward Russian troops, at a position near the front line town of Marinka, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 26, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





Ukrainian servicemen of the 55th Separate Artillery Brigade fire a M777 howitzer toward Russian troops at a position near the front line town of Marinka, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 26, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





A Ukrainian serviceman of the Ukrainian 92nd Ivan Sirko Separate Assault Brigade boils water for tea inside a dugout at a position in a front line near the town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 15, 2023. (Photo by Inna Varenytsia/Reuters)





A cat sits on the shoulder of Ukrainian serviceman Mykyta of the 93rd separate mechanized brigade at a rest house near the front line in the Donetsk region on December 25, 2023. (Photo by Thomas Peter/Reuters)





Ukrainian service members fire a L119 howitzer towards Russian troops near the front line town of Bakhmut, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on December 21, 2023. (Photo by Viacheslav Ratynskyi/Reuters)





Ukrainian servicemen carry the coffin of their comrade Vasyl Boichuk who was killed in Mykolayiv in March 2022, during his funeral ceremony at the cemetery in Iltsi village, Ukraine, Tuesday, December 26, 2023. (Photo by Evgeniy Maloletka/AP Photo)





A Ukrainian soldier of the 14th Separate Mechanized Brigade holds a candle during a Christmas Eve service near the front line outside Kupiansk, Ukraine on December 24, 2023. (Photo by Thomas Peter/Reuters)





Ukrainian service members rest inside a dugout at a position near the frontline town of Bakhmut in Donetsk region, Ukraine on December 21, 2023. (Photo by Viacheslav Ratynskyi/Reuters)