A new ‘buffer zone’? Russia advances in east-central Ukraine, pushing toward territory it does not already claim
Like our earlier reports on the combat situation in Ukraine, this article takes stock of the recent developments on the battlefield based on open-source information. Meduza has condemned Russia’s invasion of Ukraine from the very start, and our detailed military analyses are part of our commitment to objective reporting on a war we firmly oppose.
Our map is based exclusively on open-source photos and videos, most of them posted by eyewitnesses on social media. We collect available evidence and determine its geolocation markers, adding only the photos and videos that clear this process. Meduza doesn’t try to track the conflict in real time; the data reflected on the map are typically at least 48 hours old.
Key updates as of June 12, 2025
The Russian army’s offensive has accelerated simultaneously along several fronts. Russian forces deployed significant troops to the northern part of Ukraine’s Sumy region after several Ukrainian brigades were redeployed away from the area to other parts of the front. While the advance doesn’t currently pose a direct threat to the city of Sumy, Ukraine’s military command will need to find reserves to stabilize the situation.
The redeployed Ukrainian brigades, which had already sustained losses in fighting near Sudzha, have been sent to the area around Kostiantynivka in central Donbas to try to stop a Russian breakthrough. So far, they haven’t succeeded. Russian forces are advancing on Kostiantynivka from three directions: from Chasiv Yar in the east, from the south from the direction of Toretsk, and from the west along the road to Pokrovsk.
Farther west along the same road, Russian troops are attempting to break through to the northern outskirts of Pokrovsk. Meanwhile, another Russian group southwest of Pokrovsk has reached the border of the Dnipropetrovsk region and is preparing to maneuver around the city from the west. Asked if Russia’s aim was to create a “buffer zone” in the area, Kremlin spokesman Dmitry Peskov told journalists on Monday, “Without a doubt that is part of it.”
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Kostiantynivka, Toretsk, and Chasiv Yar
After heavy fighting, Russian forces from the 8th Combined Arms Army, redeployed this spring from near Kurakhove to the Toretsk metropolitan area, have broken through Ukrainian lines to both the west and east of Toretsk.
The 8th Army’s 150th Guards Motor Rifle Division managed to break through along the Nelipivka–Dyliivka axis, but only after repelling multiple counterattacks, during which Ukrainian forces twice reached central Toretsk. The division has now almost reached the eastern edge of the Kleban-Bykske Reservoir, putting Ukraine’s northern supply route at risk. However, the Kryvyi Torets River still separates Russian forces from the reservoir.
The division’s units are continuing to push toward Kostiantynivka, threatening to advance directly on the city and cut off Ukrainian forces defending positions near the Siverskyi Donets–Donbas Canal. Troops from the 150th Division are also storming the Saint Matrona Mine — the last major Ukrainian stronghold in northern Toretsk. The breakthrough toward the Kleban-Bykske Reservoir, effectively to the rear of the mine’s defenders, has made their position increasingly difficult to hold.
To the west of Toretsk, units from the 20th Guards Motor Rifle Division — also part of the 8th Army — have pushed deep into Ukrainian defenses along the Pokrovsk–Kostiantynivka road and farther south, nearly reaching the western edge of the Kleban-Bykske Reservoir near the village of Yablunivka. The main Ukrainian grouping in the area, composed of National Guard units, is currently positioned on Toretsk’s western outskirts, in the settlements of Leonidivka and Shcherbynivka. If Russian forces succeed in fully capturing Yablunivka, these Ukrainian troops risk being cut off from the rear.
Russian attacks near Toretsk are likely to soon force Ukrainian army and National Guard troops to retreat toward Kostiantynivka. Meanwhile, Russian troops have launched a new offensive on Kostiantynivka from the direction of Chasiv Yar, capturing part of a key Ukrainian stronghold in the village of Stupochky, which lies along the Bakhmut–Kostiantynivka road.
North of the Pokrovsk–Kostiantynivka road, near the village of Popiv Yar, Russian forces continue efforts to bypass Kostiantynivka from the north — advancing toward Druzhkivka and the southern outskirts of the Kramatorsk–Sloviansk agglomeration. That agglomeration appears to be the primary target of Russia’s 2025 offensive.
Pokrovsk and the border of the Dnipropetrovsk region
Contrary to the expectations of many experts, the Russian army once again did not attempt to storm Pokrovsk, a key defensive hub for Ukraine in western Donbas. Instead, they’re trying to seize positions on the flanks of Ukraine’s defense, with the apparent aim of eventually bypassing the city from two sides.
To this end, Russian forces are likely planning to break through to the north on one side, from positions on the Pokrovsk–Kostiantynivka highway near the village of Novoekonomichne, and through Novopavlivka, a village to the southwest of Pokrovsk in the Dnipropetrovsk region, on the other.
A Russian offensive in early June stopped on the outskirts of Novoekonomichne, where their path remains blocked by the Kazennyi Torets River and some of the Ukrainian reserves transferred from the Sumy region and Toretsk itself.
Southwest of Pokrovsk, Russian troops from the “Tsentr” contingent broke through the village of Horikhove to the border of the Dnipropetrovsk region. Their forward positions are now located five kilometers (three miles) from Novopavlivka. If Russian troops capture this village, they’ll be able to advance north and cut off the highway that connects Pokrovsk to the city of Dnipro.
At the same time, Russian troops from the “Vostok” contingent, which previously seized the district centers of Velyka Novosilka and Kurakhove, are breaking through to the Novopavlivka area from the south. Troops from the two groupings have closed their flanks, capturing the villages of Oleksiivka and Bahatyr. Vostok units have also approached Komar, a village further west along the Donetsk-Zaporizhzhia highway.
All of these attacks could lead to a situation where the Ukrainian Armed Forces (AFU) are forced to retreat to Novopavlivka and deep into the Zaporizhzhia region, along the Donetsk–Zaporizhzhia highway.
Sumy region
Russia has returned rested units that took part in the battle for Sudzha to the front on the border between the Kursk region and Ukraine’s Sumy region. Earlier, some experts predicted that these troops would be sent to central Donbas or to other areas in Ukraine. Instead, fresh Russian troops, as well as forces transferred from the Kharkiv area, crossed the border to the west of an existing bridgehead in the Sumy region, located near the village of Yunakivka on the Sumy–Sudzha highway.
In this new sector, Russian forces advanced five to eight kilometers (three to five miles) into the Sumy region, reaching Yunakivka from the west. There are also Russian troops located on the northern outskirts of the village.
Given the Russian army’s obvious numerical advantage in the Sumy region, the AFU may be counting on difficult terrain to halt their advance. To the south of Yunakivka is a large forested area, through which flows the Psel River and its swampy banks. The Oleshnya River also cuts off Russian troops from Sumy from the north.
Though Russia has more troops than Ukraine in this section of the front, it’s clearly not enough to storm a city as large as Sumy. That said, the AFU can’t afford to let Russian troops approach the city. Both the example of Pokrovsk in 2024–2025 and the northern outskirts of Kharkiv in 2022 show that frontline cities can be quickly reduced to ruins even without being stormed.
As the situation in Pokrovsk also shows, the defense of a city with the front line running along its outskirts, and which must not be surrendered under any circumstances, will continuously “eat up” a large number of reserves, leaving other areas exposed. What the Ukrainian command needs right now is to find forces to contain the Russian offensive on the far approaches to Sumy.
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Meduza’s Razbor (“Explainers”) team