Russian forces destroyed the critical infrastructure in the southern city of Kherson before fleeing, Ukrainian president Volodymyr Zelenskiy said on Saturday, adding that local authorities were starting to stabilise the city.
But pro-Moscow forces are putting up a much stiffer fight elsewhere and Mr Zelenskiy said the battles in the eastern Donetsk region were hellish.
Jubilant residents welcomed troops arriving in the centre of Kherson on Friday after Russia abandoned the only regional capital it had captured since the start of the war.
"Before fleeing from Kherson, the occupiers destroyed all the critical infrastructure: communications, water, heat, electricity," Mr Zelenskiy said in a video address.
"(Russians) everywhere have the same goal: to humiliate people as much as possible. But we will restore everything, believe me," he continued.
Mr Zelenskiy said Ukrainian troops had taken control of more than 60 settlements in the Kherson region.
"Police have launched stabilization measures. Stabilization measures are also underway in Kherson," he said, noting that almost 2,000 mines, trip-wires and unexploded shells had been dealt with so far.
Ukraine was able to conduct successful operations in Kherson and elsewhere in part because of resistance in the Donetsk region in the face of repeated Russian attacks, he said.
"There it is just hell - there are extremely fierce battles there every day," he said. "But our units are defending bravely - they are withstanding the terrible pressure of the invaders, preserving our defense lines."
