Russian troops are making a concerted push in eastern Ukraine and have gained a foothold in the strategic hub of Pokrovsk, Ukrainian President Volodymyr Zelensky says.

Moscow's soldiers outnumber Kyiv's 8-1 in the area, and Ukraine cannot match that, Zelensky added while insisting Russia had not yet 'achieved the planned result.'

Russia has been trying to capture Pokrovsk for two years. The key supply and transport hub provides supplies and reinforcements to the eastern front - and it would get Moscow closer to occupying the entirety of the Donetsk region.

It would also put towns of the heavily fortified 'fortress belt' - Kramatorsk, Slovyansk, Kostyantynivka, and Druzhkivka - within easier reach of Moscow.

Zelensky said drone imagery showed that around 200 Russian soldiers were inside Pokrovsk.

Describing the situation as 'difficult', he noted there was widespread fierce fighting and 'sabotage groups' had entered the town. However, he rejected reports by Russia's Chief of General Staff, Gen Valery Gerasimov, that Ukrainian troops had been completely surrounded.

In an update on Tuesday, Russia's defense ministry stated its forces had encircled Ukrainian troops around the main railway station and cleared the city's Troyanda district of Ukrainian forces.

One soldier from Ukraine's 155th Brigade, Artem Pribylnov, rejected the notion that Ukrainian troops had been encircled in a 'cauldron' at Pokrovsk.

'But the war has changed and it's very technological now,' he said.

He explained that previously, there had been paths in and out, but now drones controlled access points, making it 'extremely dangerous.'

Capt Hryhoriy Shapoval, spokesperson of Ukraine's East operational group, reported that 79 attacks had been repelled near Pokrovsk since Monday - almost a third of total assaults on the front line.

As of now, Russian troops occupy around 20% of Ukrainian territory. The ongoing conflict requires financial support from European allies for Ukraine to sustain its defensive efforts against the heightened Russian presence and advance.

President Zelensky highlighted the urgent need for stable financial backing, stressing that Ukraine would not be fighting a protracted war without it.