Ukrainian President Volodymyr Zelensky made a triumphant visit to the newly liberated city of Kherson and hailed the Russian withdrawal as the "beginning of the end of the war".
But he also acknowledged the heavy price Ukrainian soldiers are paying in their grinding effort to push back the invading force.
The retaking of Kherson was one of Ukraine's biggest successes in nearly nine months since the invasion.
It served another stinging blow to the Kremlin and could become a springboard for further advances into occupied territory.
Zelensky walked the streets of the city on Monday, just hours after warning in his nightly video address of booby traps and mines left behind by the Russians before their retreat.
"This is the beginning of the end of the war," he said.
"We are step by step coming to all the temporarily occupied territories."
The end of Russia 's occupation of the city has sparked days of celebration - but also exposed a humanitarian emergency, with residents living without power and water and short of food and medicines.
Russia still controls about 70% of the wider Kherson region.
Zelensky has previously appeared unexpectedly in other front-line areas at crucial junctures of the war and his latest visit was both laden with symbolism and the common touch - clearly aimed at boosting the morale of both soldiers and civilians alike.
In video published by a presidential aide, a visibly moved Zelensky stood with his right hand on his heart and sang the national anthem, as troops saluted and stood to attention and soldiers steadily hauled the yellow-and-blue Ukrainian flag up a flagpole.
Other footage showed Zelensky waving to residents who saluted him from an apartment window and yelled: "Glory to Ukraine!" The reply - "Glory to the heroes!" - came back from Zelensky's group, made up of soldiers and others.
The president also distributed medals to Ukrainian soldiers in a central square and posed for selfies with them.
Kremlin spokesman Dmitry Peskov on Monday refused to comment on Zelensky's visit to Kherson, saying only that "you know that it is the territory of the Russian Federation".
The Kremlin illegally annexed the Kherson region and three others earlier this year. After the Russian retreat, Ukrainian authorities say they are finding evidence of torture and other atrocities.
In his nightly video address on Sunday, Zelensky said without giving details that "investigators have already documented more than 400 Russian war crimes, and the bodies of both civilians and military personnel have been found."
"In the Kherson region, the Russian army left behind the same atrocities as in other regions of our country," he said. "We will find and bring to justice every murderer. Without a doubt."
Residents said departing Russian troops plundered the city, carting away loot as they withdrew last week.
They also wrecked key infrastructure before retreating across the wide Dnieper River to its east bank.
One Ukrainian official described the situation in Kherson as "a humanitarian catastrophe."
Reconnecting the electricity supply is the priority, with gas supplies already assured, Kherson regional governor Yaroslav Yanushevych said.
The Russian pullout marked a triumphant milestone in Ukraine's pushback against Moscow's invasion almost nine months ago.
In the past two months, Ukraine's military claimed to have retaken dozens of towns and villages north of the city of Kherson.
