Ukrainian President Volodymyr Zelensky has said the defence of Pokrovsk is a 'priority', as elite special forces were deployed to the embattled town on the eastern front line.
Ukrainian army sources told the BBC that special forces from military intelligence and assault groups were being used as regular infantry to protect supply lines to troops holding the town in the Donbas region.
There have been growing reports of Russian advances around the strategic town to the west of Donetsk. Ukraine has denied claims their forces were surrounded.
Moscow wants Kyiv to cede the entire Donbas region as part of a peace deal, including the parts it currently does not control.
Russia currently controls around a fifth of Ukrainian territory, including the Crimean peninsula it annexed in 2014.
The deployment of special forces suggests officials in Kyiv are determined to try to hold onto the town, which Russia has been trying to seize for more than a year.
Pokrovsk is a key transport and supply hub whose capture could unlock Russian efforts to seize the rest of the region.
Washington has grown increasingly frustrated with the Kremlin's failure to move forward with peace negotiations.
In his nightly address, Zelensky expressed the urgency of the situation: 'Pokrovsk is our priority. We continue to destroy the occupier, and that is what matters most.'
