After months of accelerating advances towards Pokrovsk, Russian forces are as close as 3km from the southern outskirts of the city, according to Ukraine's DeepState which maps the front lines using open sources.
"As a result of prolonged clashes, two of our positions were destroyed, one was lost. Currently, measures are being taken to restore positions," Nazar Voloshyn, Ukraine's military spokesman for the eastern front, said in televised comments.
Ukraine's army considers Pokrovsk an important logistics centre for the military. (AP PHOTO)
Pokrovsk, situated about 18km from the boundary of Ukraine's Donetsk and Dnipropetrovsk regions, has for months been the area of the fiercest battles in Russia's 33-month-old full-scale invasion of Ukraine.
In October and November, the Russian military advanced towards the city at its fastest rate since the early months of the war, analysts said.
Ukraine, which has been on the back foot since its failed 2023 counteroffensive, says Russia has been sustaining some of its heaviest losses of the war to date.
Both Ukraine and Russia have their eye on the growing prospect of a push for peace talks, with US president-elect Donald Trump preparing to enter office on January 20, having called for an immediate ceasefire and a swift end to the war.
Ukraine has urged its allies to get it into the strongest possible position on the battlefield before any talks do happen.
Russia, which Ukraine says has more than 70,000 troops on the Pokrovsk front, has rapidly advanced towards Shevchenko, a village to Pokrovsk's south, in recent weeks.
Its forces are currently trying to gain a foothold in the village and sending in reconnaissance and sabotage groups, Voloshyn said.
Ukraine is holding them back for now, he added.
The fall of Pokrovsk, an important logistics centre for the Ukrainian military in the east, would amount to the biggest military setback for Ukraine in months.
The city also hosts Ukraine's only domestic coking coal supplier for its once-giant steel industry.
The mine, which was still operating as of December 6, lies 10km west of Pokrovsk, the far side from where Russian troops have been advancing.