KYIV — Ukrainian President Volodymyr Zelenskyy on Saturday rejected Russian claims that Moscow had captured the front-line city of Kostiantynivka in the eastern Donetsk region.Zelenskyy accused Russian President Vladimir Putin of "choosing to lie to the world" about the situation on the battlefield."He claims that Russian forces have supposedly captured Kostiantynivka in the Donbas. Of course, that is not true," Zelenskyy wrote on X, calling the assertion "just another Russian lie.""If Kostiantynivka were under Russian control, then perhaps Putin would have no problem meeting me there to find a diplomatic way to finally end this war. But the fact is, he won't cross the front line — reality is very different from Putin's words," he added.Andriy Kovalev, spokesman for Ukraine's General Staff, told the Ukrainska Pravda newspaper that Ukrainian forces continue defensive operations in and around the city."The situation remains difficult but is under the control of Ukraine's defense forces," Kovalev said, adding that Russian troops carried out 11 assault attempts on July 3 without success.He also accused Moscow of spreading "disinformation and fakes" about the battlefield situation.Russia claimed on Friday that its forces had taken full control of the industrial city of Kostiantynivka."The main news is that Kostiantynivka has been completely taken," Kremlin spokesman Dmitry Peskov told reporters.Peskov said Putin had thanked the Russian troops involved in the operation and described the city's capture as "the first, but very important, stage in the capture of the already important Sloviansk-Kramatorsk defensive hub of the Ukrainian Armed Forces."Kostiantynivka lies about 24 kilometers (15 miles) southeast of Kramatorsk, which has served as the administrative center of the Donetsk region since Russia seized much of the region in 2014.