• Ukraine rejects Russian claim of capturing Kostiantynivka in eastern Ukraine, with ongoing fighting reported in the town and surrounding villages.
• Ukrainian President Zelensky challenges Putin to meet in Kostiantynivka, dismissing Russian announcement as "another lie" and Kremlin rejecting the offer for talks in the town.
• Russian forces make territorial gains in Kostiantynivka, with Putin emphasizing battlefield successes amid fuel crisis in Russia and aim to bring Donbass region under Russian control.

Ukraine on Saturday rejected Moscow's claim that Russian forces had captured the town of Kostiantynivka in the Donbass industrial region of eastern Ukraine.

The Ukrainian General Staff's morning report said fighting was continuing in the town, which once had a population of 67,000. Clashes were also ongoing in villages even closer to Russian positions, including Ivanopylia.

Russian President Vladimir Putin had said the previous evening during a visit to a command centre that the Russian army had brought Kostiantynivka fully under its control. Ukrainian military blogs such as DeepState continue to list only parts of the town as being under Russian occupation, while Russian military bloggers have not so far claimed the entire settlement for Moscow's forces.

Ukrainian President Volodymyr Zelensky dismissed the announcement as "another Russian lie to start some news" during a phone call with German Chancellor Friedrich Merz," Zelensky's office said in a summary of the conversation.

Zelensky challenged Putin to meet him in Kostiantynivka.

"If Kostiantynivka were currently under Russian control, Putin would probably have no problem meeting me there and finding diplomatic solutions to finally end the war," he said. "But he will not cross the front line. The truth is very different from Putin's words."

The Kremlin swiftly rejected the offer to hold talks in Kostiantynivka.

Zelensky could come to Moscow if he was prepared to make responsible decisions, Kremlin spokesman Dmitry Peskov said, according to the state news agency TASS.

Peskov recalled that Russian President Vladimir Putin had previously expressed his willingness to receive Zelensky in Moscow.

"After all, Moscow is the capital of the Russian Federation, not Kostiantynivka," he said.

Zelensky has categorically ruled out a visit to Moscow.

Institute: Putin needs positive news

The US Institute for the Study of War (ISW) said Russian forces had made territorial gains in Kostiantynivka in recent weeks. However, the Russian presence in the town primarily consists of small assault groups operating between Ukrainian positions.

The Russian president appeared in military uniform for the first time in a long while during his visit to the command centre. Announcing battlefield successes remains important for Putin as a fuel crisis in Russia, triggered by Ukrainian drone attacks, has fuelled public discontent.

One of Putin's stated war aims is to bring the Donbass, Ukraine's industrial and coal-mining heartland, entirely under Russian control. If Kostiantynivka were to fall, only Sloviansk, Kramatorsk and Druzhkivka would remain under Ukrainian control among the larger cities in the Donetsk region.