The Institute for the Study of War (ISW) reported that the Russians were "emphatically not attempting to establish and strengthen defensive positions all along the line," but were "rather renewing offensive operations in Donetsk Oblast."
Meanwhile, "the Ukrainians will almost certainly continue their counter-offensive operations already underway," the Washington-based think tank said in its latest analysis of Russia's military campaign in Ukraine.
Both sides "are already fighting in very muddy conditions," according to the ISW.
It said: "They will not likely stop fighting when winter freezes the ground and makes it even more conducive to large-scale mechanized maneuver warfare. Combat is more likely to intensify than to slacken as temperatures drop."
The ISW observed that "any attempt at a ceasefire or cessation of hostilities at this time would overwhelmingly favor Russia."
According to the ISW, the Russians "are not setting conditions for a relaxation of hostilities for the rest of the fall and into the winter but rather are launching a new offensive in Donetsk Oblast."
The Ukrainians, meanwhile, "will likely use combat power recouped from the liberation of western Kherson to reinforce their ongoing counter-offensive in Luhansk Oblast or to open a new counter-offensive drive elsewhere," it said.
"This is not the time to slow down aid or press for ceasefires or negotiations, but rather the time to help Ukraine take advantage of its momentum in conditions that favor Kyiv rather than Moscow," the ISW said.
Ukrainian President Volodymyr Zelensky said on Sunday that investigators had uncovered more than 400 Russian war crimes in his country's southern Kherson region after the withdrawal of Russian forces.
Zelensky last Friday announced the liberation of the southern city of Kherson after Russian forces withdrew from the area earlier that day.
Monday is day 264 of the Russian invasion of Ukraine.
Source: PAP, understandingwar.org