The battle for Kherson looms as a pivotal moment for both Ukraine and Russia, experts say — Ukraine retaking the city would be a huge blow to Russia and an embarrassing setback for President Vladimir Putin.
Kherson, situated on the Dnieper River in Ukraine's south, was the first major Ukrainian city to fall to Russian forces back in early March, and represented an early success for Moscow.
Ukrainian forces are advancing on the city, and on Saturday the Ukrainian military's southern command said more than 100 Russian soldiers had been killed and seven tanks destroyed in fighting in the area, while residents have been urged to leave.
Those who remain in the city have been living in a de facto Russian state since it was taken over, and are facing a "ticking clock" with expectations a rigged referendum will be held for the region to join Russia.
Britain's Ministry of Defence said Kherson was now "virtually cut off" from other territories occupied by Russian and Russian-backed forces.
"Its loss would severely undermine Russia's attempts to paint the occupation as a success," it said in a statement.
Kherson is seen as a gateway to the strategic port city of Odesa in Ukraine's south-west, and losing it would also mean Russia could face issues supplying Crimea, which it annexed in 2014, with fresh water.
Kori Schake, the director of foreign and defence policy at the American Enterprise Institute, said Kherson was "enormously important economically for Ukraine".
"A lot of the power generation in the country is there, a lot of the industry of the country is in and around there and requires transportation from Kherson," Dr Schake, who also held high positions at the US Defence Department and National Security Council, told the ABC.
"But it's also incredibly symbolically important to Ukraine.
"A big victory would remind Russia, and also other countries, that Ukraine not only can win this war, but is winning this war.
"Russia has picked up small, strategically unimportant gains – Kherson is strategically important, and Ukraine retaking it as the offensive, which it appears is commencing, that would be a very important signal both for Ukraine and for Russia."
HIMARS doing the damage
Ukraine's capability to be able to launch a counterattack to retake Kherson has been largely down to one thing – HIMARS — according to analysts and those using it on the ground.
The introduction of the US-supplied M142 High Mobility Artillery Rocket System (HIMARS) to Ukrainian forces in late June has had a huge effect on the battlefield.
The system's GPS-guided rockets provide Ukraine with the ability to hit specific targets, such as ammunition dumps and supply lines, with greater precision and at further distances than ever before.
"It's allowed Ukraine's military to target Russian logistics nodes, ammunitions supply, and that makes it harder for the Russians to get weapons to their own forces in Kherson and other places," Dr Schake said.
This was evident last week when Ukraine struck the Antonivskyi Bridge – the main crossing over the Dnieper River in the Kherson region – and a link vital to the Russian military being able to supply its troops in the area.
"Our gunners use HIMARS very delicately — like a surgeon with a scalpel, they work," Ukrainian Defence Minister Oleksiy Reznikov said on national television after the attack.
Britain's Ministry of Defence said Russia had likely established two pontoon bridges and a ferry system to compensate for the loss of the bridge, but the loss of rail traffic across the bridge will severely hamper Russia's 49th Army, which is stationed on the west bank of the river.
Justin Crump, a former tank commander in the British Army and CEO of risk analysis company Sibylline, said Russia had underestimated the Ukrainian forces' ability to effectively use HIMARS.
"I think it's been helped by the fact that the Russians, as they have throughout this conflict, believe their own capabilities and underrated the capabilities of the adversary consistently," he said.
"They did with these missiles as well.
"Their ammunition depots were in the places in some instances they've been since 2015, everyone knew where they were, you'd see them on Google Maps, you know, some signposts at the entrance."
The success of HIMARS has even lauded in a string of anti-occupation posters that have been placed around the city in recent weeks.
Slogans on the posters include "Occupier, leave now – or this HIMARS will help you on your way".
The success of HIMARS has seen Russia increase its attacks on southern cities around Kherson, including the heavy shelling of nearby Mykolaiv on the weekend.
One of Ukraine's richest men, grain exporter Oleksiy Vadatursky, was reportedly killed alongside his wife when a Russian missile hit their home.
President Volodymyr Zelenskyy described Mr Vadatursky's death as "a great loss for all of Ukraine".
Time running out to prevent Russian annexation
In April, Russia installed a pro-Kremlin administration in the city, filled the streets with propaganda and posters, started broadcasting Russian television and began transitioning the economy to the Russian rouble.
Many of the city's residents demonstrated against the occupiers, but dissent was quickly met with force and stamped out, while thousands of others fled the city.
Russia also began offering passports to Kherson's residents, with officials claiming more than 2,000 had already been handed out and another 11,000 had been applied for.
It is all paving the way for Russia to annex the region through a referendum planned by the local administration that would decide if it would join the Russian Federation.
Last week, Kirill Stremousov, the deputy head of the Kherson Military-Civilian Administration who is seen as one of Putin's "puppet governors", hit out at Ukraine's plans to counterattack and retake Kherson, saying they would be sending people "to their certain deaths".
"We want to say that no matter what you do: criminal responsibility, intimidation, information terror, there will still be a referendum in the Kherson region that will clearly define the region as part of the Russian Federation," he said in a video message posted to the Telegram app.
Mr Stremousov added that the referendum would be held soon, with expectations that there could be a vote by September.
That is a date that the Ukrainian forces would have firmly in their mind, Mr Crump said.
"September is probably a ticking clock for Ukraine to try and make sure that they've got something they can they can disrupt that (referendum), not that it would be taken seriously anyway, but it's obviously doubly satisfying if you can stop them from doing it," he said.
"And there is the risk that the second they have that referendum, Putin declares it Russian territory.
"There is a real fear that once this is declared Russian territory, attacking that might invite much harsher responses, the same as it would if they went (and attacked) Moscow."
Kori Schake said Russia's bullying tactics were not working.
"What Russia's trying to do is show that Ukraine isn't united and that the West won't support it," she said.
"And so far, Russia has been unable to prove either of those two things."
