Ukrainian officials say Ukrainian flags have been appearing "en masse and all over the place" following Russia's retreat from the southern region of Kherson, one of the four regions in Ukraine Russian President Vladimir Putin annexed in September.
The months-long Ukrainian offensive to recapture the city of Kherson, the only provincial capital that has been under Russian control since the early days of the invasion, is coming to a head.
The fall of the city would deal another humiliation to Moscow after a string of battlefield defeats and other setbacks.
Here's a look at what has been happening and why Kherson is such an important city for both sides.
Why is the city prized?
Kherson, which had a pre-war population of 280,000, is the only regional capital to be captured by Russian forces.
The city and surrounding areas fell into Moscow's hands in the opening days of the war as Russian soldiers quickly pushed their attack north from the Crimean Peninsula — the region illegally annexed by the Kremlin in 2014.
Its loss was a major blow to Ukraine because of its location on the Dnipro River near the mouth of the Black Sea, and its role as a major industrial centre.
Ukrainian resistance fighters have challenged Russian forces for control of the city ever since, with acts of sabotage and assassinations of Moscow-appointed officials.
Kherson also sits at a point where Ukraine can cut off fresh water from the Dnipro River to Crimea.
Kyiv blocked those vital supplies after the Crimean Peninsula's annexation, and Mr Putin mentioned the need to restore them as one reason behind his decision to invade Ukraine.
What is happening there?
In the past day, Ukrainian forces have made gains north-west, west and north-east of the city of Kherson, advancing up to 7 kilometres in some areas, according to the Institute for the Study of War, a Washington-based think tank.
"Russians have moved to positions they hope will be easier to defend. Ukraine will have to decide whether, when, and how to keep pushing," said Olga Oliker, director for Europe and Central Asia at the International Crisis Group.
"But Ukraine seems on the verge of taking back … and this is very good news for Mykolaiv, which Russia will now have a much harder time bombarding.
"It is a serious Ukrainian advance."
Kherson's Ukrainian-appointed regional official, Serhii Khlan said as Russia pulled back from the western bank of the river that divides the region, they have left behind wreckage and destroyed key infrastructure, including power facilities and bridges.
"It will all have to be reconstructed," he said.
"While fleeing, they were blowing up everything, everything that could deter the [Ukrainian] advance."
Mr Khlan advised civilians to stay home and said the humanitarian situation was really complicated, with power supplies cut off and very limited communications.
What would losing Kherson mean for Russia?
The Kremlin has remained defiant, and has insisted battlefield developments in the Kherson region in no way represented an embarrassment for Mr Putin.
Fearing such a major Ukrainian counterattack, the Kremlin-installed regional administration in Kherson reportedly relocated at least 70,000 residents earlier this month.
A retreat from Kherson and other areas on the Dnipro River's west bank would shatter Russian hopes to press an offensive west to Mykolaiv and Odesa to cut off Ukraine's access to the Black Sea.
Moscow had also hoped to build a land corridor to the separatist Transnistria region of Moldova, home to a major Russian military base.
"The loss of Kherson will turn all those southern dreams by the Kremlin into dust," Ukrainian military analyst Oleh Zhdanov said.
"Kherson is a key to the entire southern region, which would allow Ukraine to target key supply routes for the Russian forces. Russians will try to retain control of it using all means."
What would recapturing the city mean for Ukraine?
For Ukraine, recapturing Kherson would set the stage for reclaiming the Russia-occupied part of the Zaporizhzhia region and other areas in the south, and eventually pushing back into Crimea.
Reclaiming control of Kherson would also mean that Kyiv could again cut off water to Crimea.
"After the de-occupation of Kherson, the Russians will again have problems with fresh water in Crimea," Mr Zhdanov added.
Volodymyr Fesenko, head of the Kyiv-based Penta Center independent think tank, said controlling the Kherson region and other southern areas was a major prize for Russia.
Their loss would have painful consequences for Mr Putin at home and abroad.
"If the Russians leave Kherson, the Kremlin will face another wave of fierce criticism of the military command and the authorities in general from ultra-patriotic circles," Mr Fesenko said.
The fall of the city would further demoralise Russia's armed forces and possibly fuel opposition to the mobilisation effort, he said.
He also said China and India would see the fall of Kherson as a sign of Kremlin weakness.
"Mr Putin will face reputational losses not only inside the country, but also in the eyes of China, and that could be particularly dangerous for the Kremlin," Mr Fesenko said.
AP/ABC
