All bridges out of the eastern Ukrainian city of Syevyerodonetsk have been destroyed and conditions for people remaining in the city are "extremely difficult," the military governor for the Luhansk region told RFE/RL.
"All the bridges have been destroyed, so it is impossible to bring anything to the city today, unfortunately," said Serhiy Hayday, adding that evacuations were not possible.
Russian forces have destroyed the entire infrastructure for gas, water, and electricity, he said, noting there were also "huge problems" with medical care.
According to Hayday, the Russian Army currently controls 70 percent to 80 percent of Syevyerodonetsk.
He added on Facebook that Syevyerodonetsk was not blocked, and there is communication with the city.
The Ukrainian military said that its forces were pushed back from the center of Syevyerodonetsk, the Donbas city that has seen ferocious battles as Ukrainian and Russian forces fight for control.
Eduard Basurin, a senior separatist figure, said on June 13 that Syevyerodonetsk had been "de facto" blocked off after Russian forces blew up the "last" bridge connecting it to Lysychansk.
Ukraine's General Staff said earlier that Russia troops had gained a foothold in the village of Bohorodychne, a village about 50 kilometers west of Syevyerodonetsk.
Taking Bohorodychne puts Russian forces in good position to attack Slovyansk, a bigger, more important town.
According to Basurin, Moscow-backed forces have begun an offensive on Slovyansk.
Hayday commented earlier about the situation at the Azot nitrogen chemical plant in Syevyerodonetsk, where hundreds of civilians have reportedly taken refuge, saying it was being "heavily shelled."
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Moscow-backed separatist fighters said over the weekend that they had surrounded the plant and claimed that Ukrainian defenders were trapped there.
The claims could not be independently confirmed.
President Volodymyr Zelenskiy said in his nightly video address on June 13 that the battle for Syevyerodonetsk was taking a "terrifying" toll.
"The human cost of this battle is very high for us. It is simply terrifying," Zelenskiy said.
He told Ukrainians on June 12 that Russia's "key tactical goal" had not changed.
"They are pressing in Syevyerodonetsk, severe fighting is ongoing there -- literally for every meter," Zelenskiy said, adding that Russia's military was trying to pour reserves into the Donbas.
Zelenskiy said Russia was deploying undertrained troops and using its young men as "cannon fodder" in the "very fierce" battle.
"Every meter of Ukrainian land there is covered in blood -- but not only ours, also the occupier's."
The British Defense Ministry said in its daily intelligence bulletin on June 13 that in the coming months, river crossing operations "are likely to be amongst the most important determining factors in the course of the war."
The British intelligence said Russia had so far struggled to demonstrate the "complex coordination necessary to conduct successful, large-scale river crossings under fire."
Despite the increasingly difficult situation, Zelenskiy remained defiant, saying that Ukrainian forces have prevented Russian troops from quickly overrunning eastern Ukraine.
"Remember how in Russia, in the beginning of May, they hoped to seize all of the Donbas?" Zelenskiy said. "It's already the 108th day of the war, already June. Donbas is holding on."
Syevyerodonetsk has been the focal point of recent fighting that Kyiv has said could determine the outcome of the war, which began on February 24 with Russia’s unprovoked, full-scale invasion of Ukraine.
The city itself has been all but turned into rubble by the Russian forces' shelling, with the situation resembling conditions seen at the southern port of Mariupol, which fell to Russian forces after a long, bloody battle last month.
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In the western region of Ternopil, at least 22 people were wounded when four Russian cruise missile hit a military installation and some residential buildings, the regional governor said on June 12.
Mykhaylo Podolyak, a top adviser to Zelenskiy, meanwhile, made a plea for thousands of heavy weapons and equipment to achieve parity with Russia at the front and end the war.
"Being straightforward -- to end the war we need heavy weapons parity," he said on Twitter. He listed 1,000 howitzers, 300 multiple launch rocket systems, 500 tanks, 2,000 armored vehicles, and 1,000 drones.
"Contact Group of Defense Ministers meeting is held in #Brussels on June 15. We are waiting for a decision," he said.
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Ukrainian troops "are doing everything to stop the offensive, as much as they possibly can, as long as there are enough heavy weapons, modern artillery -- all that we have asked for and continue to ask for from our partners,” he said.
Zelenskiy asserted Russia wanted to destroy every city in the Donbas, the eastern Ukrainian region that includes the Donetsk and Luhansk regions.
“Every city, that’s not an exaggeration,” he said. “All of these ruins of once-happy cities, the black traces of fires, the craters from explosions -- this is all that Russia can give to its neighbors, to Europe, to the world.”