Speaking at a Southeast Asia summit in Cambodia on Saturday, Ukrainian Foreign Minister Dmytro Kuleba said the struggle to liberate his country would carry on.

"We are winning battles on the ground. But the war continues," he said. "I understand that everyone wants this war to end as soon as possible. We are certainly the ones who want it more than anyone."

On Friday, the Ukrainian army entered Kherson, a strategic port city on the Black Sea, following Moscow's withdrawal of its forces.

It was one of the first city Ukrainian cities to fall to Russia's military after it invaded Ukraine in February.

"As long as the war continues, and we see Russia mobilizing more conscripts and bringing more weapons to Ukraine, we will of course continue to count on your continued support,” said Kuleba.

Major allies of Ukraine hailed the liberation of Kherson on Saturday morning.

"It seems that the Ukrainians have just won an extraordinary victory: the only regional capital that Russia seized in this war is now back under the Ukrainian flag, which is quite remarkable," said US national security officer Jake Sullivan.

The UK branded Russia's pullout a tactical blunder, with Defense Minister Ben Wallace claiming it would sow doubt amongst the Russian public.

"Russia's announced withdrawal from Kherson marks yet another strategic failure for them," he said in a statement. "In February, Russia failed to seize the major targets it had set itself, apart from Kherson."

"Now, with [this city] also abandoned, people in Russia must be wondering: What is all this for," Wallace added.

In his nightly address on Friday, the Ukrainian President Volodymyr Zelensky said it was a moment of history for Ukraine.

“Today is a historic day. We are taking back the south of the country, we are taking back Kherson,” said Zelensky in a speech which was shared widely on social media.

"The special forces are already in the city," he added, saying that their first job would be to clear up mines left by the Russian army as boobytraps.

Kherson was occupied by Russian forces in mid-March. The region around the city, home to 250,000 people before the war, has been a flashpoint between Kyiv and Moscow, with the Ukrainian army pressing into the area for months.

The advance is the most significant development in the Ukraine war months. Russian forces retreated from the northeastern Kharkiv region in September, following a lightning offensive by Ukrainian troops.

The mood in Kyiv was jubilant on Friday evening, with locals and refugees from Kherson celebrating on Maidan Square.

“Finally my free city, the one where I was born, where I lived all my life”, said Nastia Stepenska, who was partying on the emblematic square in the Ukrainian capital.

"When they [the Russians] arrived, it was horrifying, we didn't know what would happen the next day, if we would stay alive", said the 17-year-old schoolgirl, with tears in her eyes and Ukraine's national colors painted on her cheeks.

Earlier Friday, the Russian Ministry of Defense announced at 5:00 a.m. Moscow time that it had completed "the redeployment" of its units from the western bank of the Dnieper River, where Kherson is located, towards the left bank.

According to Moscow, "more than 30,000" Russian soldiers and "nearly 5,000 units of armaments and military vehicles" were "withdrawn" from the city, ensuring that they did not suffer any losses or abandoned military equipment.

In September, Russian President Vladimir Putin declared that his country had annexed four Ukrainian regions, which included Kherson.

Despite the withdrawal, Kremlin spokesman Dmitry Peskov said on Friday that Kherson remains part of "the Russian Federation".

"There can be no change," he added.