Russian forces are slowly tightening the noose around the eastern Ukrainian city of Pokrovsk, a key logistical hub whose main supply lines are under threat nearly three years after Moscow invaded its neighbour.

While Ukraine is stubbornly defending the city, its encirclement or fall could put Russia in a strong position to mount attacks in several directions in the east and increase pressure on Kyiv at a critical juncture in the war.

Inside Pokrovsk, life is bleak. According to the regional governor, 7,000 residents remain out of a pre-war population of 60,000. The last post office recently closed - mail will now be delivered by armoured truck.

On either side of the city, Russian troops are within artillery and drone range of a crucial highway that runs east to west along the entirety of Ukraine, and most cars now take detours along backroads into Pokrovsk for their safety.

In the past several days, Moscow’s forces have reached the main rail line into the city from eastern Ukraine’s most important logistical hub, the city of Dnipro.

“The situation is generally difficult, the enemy is constantly attacking on foot,” said the deputy commander of Ukraine’s 59th assault brigade, which is fighting on the Pokrovsk front.

He asked to be identified by his military call sign, Phoenix, for security reasons.

The officer said the enemy had much greater numbers of infantry, attacked in small groups willing to take extremely high casualties and adeptly exploited the landscape and low-visibility weather conditions to hide themselves from drones.

“Day and night they are moving forwards,” Phoenix told Reuters.

Pokrovsk’s road and rail connections have made it an important supply centre for a large section of Ukraine’s frontline, although in recent months the threat of Russian artillery and drones has limited that function.

Michael Kofman, a senior fellow at the Carnegie Endowment for International Peace in Washington, said Pokrovsk’s transit routes meant that if it fell, Russian forces could use it as a staging ground to push north or west.

“It sets up Russian forces for a potential advance into Dnipropetrovsk region ... further behind the frontlines, they’re building and repairing rail lines.”

“They can then move up their own logistics and that enables them to push further west.”

Dnipropetrovsk region is a large province whose eastern tip faces Pokrovsk, and Russian troops are currently about 5 km (3 miles) from its boundary. It is not one of the four Ukrainian regions claimed by Russia.

With US President Donald Trump pressing the sides to reach a peace deal, Moscow’s occupation of a part of this region could strengthen its hand in future negotiations.

CHANGE IN TACTICS

Viktor Trehubov, a Ukrainian military spokesman, said the Russians were attempting to bypass and surround Pokrovsk from the west.

He said this differed from their approach to taking previous big urban areas, where they opted for costly frontal assaults and street fighting.

“It seems that, perhaps for the first time, they have started to spare their manpower,” he said.

Three analysts Reuters spoke to said that should it capture the city, Russia had two main options for advancing on the Pokrovsk axis of battle.

The first was to push westward into the sparsely populated plains of Dnipropetrovsk region, which are lightly fortified and offer few natural or urban obstacles for Kyiv to use in defence.

The second was to push north, into a denser patchwork of industrial towns that would be tougher to get through but would enable Moscow to put pressure on Kramatorsk and Sloviansk, the two biggest remaining Ukrainian-controlled cities in the eastern region of Donetsk.

On Sunday, President Volodymyr Zelenskiy put one of Ukraine’s most senior generals, land forces chief Mykhailo Drapatyi, in charge of the strategic command that oversees a vast chunk of frontline including Pokrovsk.

“He’s a well-respected commander and his appointment might lead to improved command and control and coordination between units on the frontline, which has remained a challenge for Ukraine over the past year,” said Rob Lee, a senior fellow at the US-based Foreign Policy Research Institute.

Russia’s assaults on the Pokrovsk front are largely conducted by small groups of infantry that use villages and treelines to dig in, said military spokesman Trehubov.

Phoenix, the deputy brigade commander, said the Russians had recently started using a new tactic - sending three- or four-man infantry squads deep into enemy territory to ambush Ukrainian soldiers and vehicles with the help of anti-tank mines.

However, he added that overall the assaults had become slightly less intense over the past month, and that Russia was firing less artillery than six months ago.

Pasi Paroinen, an analyst with the Finland-based Black Bird Group, said Ukraine struggled to beat back Russia’s small infantry assaults because it lacked sufficient manpower of its own to comprehensively cover the front lines.

Kyiv has faced long-running recruitment and mobilisation issues, and last year there was a rise in soldiers deserting and absconding from a depleted, tired force.

“Ukrainian units are simply running out of infantry,” Paroinen said.