As bitter fighting raged in the city of Sievierodonetsk, Ukraine's president hailed his country's fighters for defying Russian forces in his country's eastern Donbas region.
"Remember how in Russia, in the beginning of May, they hoped to seize all of the Donbas?" Volodymyr Zelenskyy said in a late night video address. "It's already the 108th day of the war, already June. Donbas is holding on."
He added that Moscow had suffered "significant" losses as it attempted to capture Ukrainian held territory in the region that borders Russia, large parts of which have been controlled Kremlin-backed separatists for more than eight years.
But as Russian advances toward its larger goal of seizing the industrial region, which is made up of the Luhansk and Donetsk provinces, the street-by-street battle for Sievierodonetsk has become the focus of the conflict.
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Luhansk Gov. Serhiy Haidai said in a Telegram post Sunday that Russian forces were "heavily shelling" parts of the city. "No one can say whether and how many victims there have been in the last 24 hours in Sievierodonetsk," he said.
In a separate interview on Ukrainian television he said that the Azot chemical plant, where hundreds of civilians were sheltering, had also been bombarded.
NBC news has not been able to independently verify his claims, but Rodion Miroshnik, the ambassador to Russia from the self-proclaimed "Luhansk People's Republic," said Saturday that 300 to 400 Ukrainian troops remained blockaded inside the plant along with several hundred civilians.
He said that Russian forces had established contact with the Ukrainian troops to arrange the evacuation of the civilians, but the the troops will be allowed to leave only if they lay down their arms and surrender.
Similar conditions existed for weeks at the Azovstal steel plant in the southern city of Mariupol before a civilian evacuation was arranged and the defending troops were ordered by Ukrainian military commanders to stand down. The fighters who came out of the Mariupol plant were taken prisoner by the Russians.
Elsewhere, the Institute for the Study of War, a Washington-based think tank, said in its latest assessment that Ukrainian intelligence suggested the Russian military was planning "to fight a longer war."
Citing the deputy head of Ukraine's national security agency, it said the intelligence "likely indicates the Kremlin has, at a minimum, acknowledged it cannot achieve its objectives in Ukraine quickly and is further adjusting its military objectives in an attempt to correct the initial deficiencies in the invasion."
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Moscow had extended its war timeline until October, with adjustments to be made depending on any successes in the Donbas, according to the assessment.
Zelenskyy appeared to acknowledge this in his late-night address. "No one can say now how long this burning of souls by Russia will last," he said.