Analysts say fierce fighting is expected to continue in the southern Ukrainian region of Kherson, as the withdrawal of Russian troops from a strategically important area in the region is likely to take time.

Russia's defense ministry said its troops began withdrawing to the east bank of the Dnipro River on Thursday. This followed an earlier announcement that it would pull out of the western bank, which includes the regional capital of Kherson.

Ukrainian President Volodymyr Zelenskyy said, "41 settlements were liberated," stressing that Ukrainian forces were regaining territory.

But Ukrainian defense minister Oleksii Reznikov warned that approximately 40,000 Russian personnel were in the Kherson district and that they had also been seen on the western bank of the Dnipro River.

The US think tank Institute for the Study of War said in an analysis that Ukrainian forces steadily advanced in Kherson on Thursday. But it went on to say, "The Russian withdrawal will take some time to complete, and fighting will continue throughout Kherson." It said Ukrainian troops will "come up against pre-prepared Russian defensive lines, especially around Kherson City."

The think tank also said, "A ceasefire would provide the Kremlin with the pause it desperately needs to reconstitute Russian forces."

Britain's defense ministry noted in an intelligence update on Friday that Kyiv has been notably impacted by Russian strikes on Ukraine's electric power infrastructure and hydroelectric dam facilities since October 10.

The ministry said Russian strikes on power generation and transmission are "indiscriminately impacting critical functions such as healthcare and heating."

It added that Russia continues to prioritize hitting critical national infrastructure over military targets, which strongly shows "Russian intent to strike at civilian morale."