Ukraine is in the midst of an "extremely dangerous" moment, officials have warned, after Russia launched a shock offensive on the Ukrainian border which threatens to open up a new front altogether as the conflict grinds on.
Russian forces smashed through the border into Ukraine's North-eastern Kharkiv region on Friday - miles away from the heaviest-hit battlegrounds in the country's south and east - with Putin's military claiming it has so far taken control of at least nine villages.
Kharkiv's regional governor, Oleg Synegubov, said: 'All areas of the northern border are under enemy fire almost around the clock - the situation is difficult."
But Ukrainian bosses have remained resolute; the country's chief commander, Oleksander Syrskyi, said on Sunday that his forces were doing all they could to hold the line.
In a statement on Telegram, Syrskyi said: "Units of the Defense Forces are fighting fierce defensive battles, the attempts of the Russian invaders to break through our defenses have been stopped.
"The situation is difficult, but the Defense Forces of Ukraine are doing everything to hold defensive lines and positions [and] inflict damage on the enemy."
A Ukrainian military spokesperson, Nazar Voloshyn, said the main thrusts of Russia's attack were aimed at the towns of Vovchansk and Lyptsi - the latter of which sits just 12 miles from the edge of Kharkiv, Ukraine's second-largest city.
A soldier with the call sign Horets told Reuters that fighting had reached Vovchansk, saying: "They [Russians] were pushing us harder... Their tank arrived and the Russian assault began. Our boys got surrounded."
The soldier said battles remained "on the outskirts of town, not inside the town", adding: "The town is ours. They are biting on the outskirts, but we are biting back. And we will bite for every metre."
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While Ukraine's President Volodymyr Zelensky said "defensive battles" were taking place along large sections of the border.
Zelensky said: "There are villages that have in fact been turned from a 'grey zone' into a zone of hostilities... The occupier is trying to gain a foothold in some of them, while others are being used to advance further."
On the ground, a senior police officer from Vovchansk helping to coordinate civilian evacuations, Oleksiy Kharkivsky, said the city was "constantly under fire".
Kharkivsky continued: "Everything in the city is being destroyed... You hear constant explosions, artillery, mortars. The enemy is hitting the city with everything they have.
The official estimated that roughly 1,500 people had been evacuated or fled the embattled Vovchansk since Friday, there had been 32 drone strikes on the town in the last 24 hours alone, and evacuation teams had come under fire "many times".
Foreign Secretary Lord Cameron described the surprise Russian offensive in Kharkiv as an "extremely dangerous" moment.
Speaking to Sky News, the Foreign Secretary said: "This only underlines that this is an unjustified, illegal invasion by Putin into an independent, sovereign country... and he's now, as it were, invaded it again from the north of Kharkiv... We must do everything we can to help the Ukrainians."
Lord Cameron talked up the UK's £3billion annual pledge to Ukraine, which he said would continue "year after year", and encouraged allies to do the same.
But Ukraine has said months of delays before the US Congress voted through a massive aid package last month have cost it on the battlefield, and the country now hopes significant quantities of the newly approved assistance will arrive quickly to shore up their defence efforts.
