Ukrainian President Volodymyr Zelenskyy met with Ukraine’s top general Thursday and told him it’s time for someone new to lead the army.

In a post on social media, Zelenskyy said he thanks Gen. Valerii Zaluzhnyi for his two years of service. “The time for such a renewal is now,” Zelenskyy said.

Zelenskyy said he has appointed Сol. Gen. Oleksandr Syrskyi, the commander of Ukraine’s ground forces, to lead the army. Syrskyi, 58, has since 2013 been involved in the Ukrainian army’s effort to adopt NATO standards. Zaluzhnyi, in a Telegram message, did not announce he had stepped down but said he accepted that “everyone must change and adapt to new realities” and agreed that there is a “need to change approaches and strategy” in the war.

The statement followed days of speculation spurred by local media reports that Zelenskyy would sack Zaluzhnyi, a move that would amount to the most serious shakeup of the top military brass since Russia’s full-scale invasion of Ukraine.

Zelenskyy said in his social media post Thursday that he offered Zaluzhnyi to “remain part of the team” without providing any details.

“We will definitely win! Glory to Ukraine!” Zelenskyy wrote.

Meanwhile, Ukrainian forces claimed to have shot down a Russian attack helicopter in eastern Ukraine near the city of Avdiivka, where soldiers are fighting from street to street as Russia’s army steps up its four-month campaign to surround Kyiv’s defending troops.

Ukrainian soldiers used a portable anti-aircraft missile to take down the Ka-52 Alligator attack helicopter, one of the Russian air force’s deadliest weapons, according to Oleksandr Tarnavskyi, the commander of Ukrainian units fighting on the southeastern front line.

The roughly 1,500-kilometer line of contact has shifted little during recent months of wintry weather. But as the war in Ukraine nears its two-year anniversary, Avdiivka has become “a primary focus” of Moscow’s forces, the U.K. Defense Ministry said in an assessment Thursday.

Street-to-street combat is taking place in the city as Ukrainian troops seek to keep open their main supply route amid intense bombardment, the ministry said on X, formerly known as Twitter.

The General Staff of Ukraine’s armed forces reported Thursday that its troops had fended off 40 enemy assaults around Avdiivka over the previous 24 hours. That is roughly double the number of daily Russian assaults at other points along the front line.

Russia’s Pravda newspaper reported Thursday that the Russian army was attempting to cut a key logistics supply route for Ukraine in the village of Lastochkyne, about 4 miles west of Avdiivka.

The Russian military has used electronic warfare to take out the Starlink communications system which Ukrainian troops use to communicate, Pravda said.

Ukraine has built multiple defenses in Avdiivka, complete with concrete fortifications and a network of tunnels. Despite massive losses of personnel and equipment, Russian troops have slowly advanced since October.

The fight has evolved into a gruesome effort for both sides. It has been compared to the nine months of fighting for Bakhmut, the Ukraine war’s longest and bloodiest battle. It ended with Russia capturing the bombed-out, deserted city last May in what Moscow hailed as a major triumph.

Both Bakhmut and Avdiivka are located in Ukraine’s Donetsk region. Moscow-backed rebels seized part of the region in 2014 and Russia illegally annexed all of it in 2022 with three other Ukrainian regions.

Russia wants to capture the entire Donetsk region, where it currently holds just over half of the territory.

Last month, Russia and Ukraine exchanged hundreds of prisoners of war, exactly a week after Moscow accused Ukraine of shooting down a military transport plane carrying dozens of captured Ukrainian soldiers. Moscow said the plane was brought down by Ukrainian missiles over far-Western Russia on its way to a prisoner swap, killing everyone on board.

Ukraine did not explicitly deny shooting down the Russian plane, but its intelligence directorate accused Moscow of failing to notify Ukrainian authorities of any flight carrying POWs, suggesting Russia may have deliberately put the Ukrainian troops in harm’s way amid increased Ukrainian attacks on Russian territory.