On 19 February 2025,
Russian President Vladimir Putin announced on a televised broadcast that the
810th Brigade had crossed the border between the Russian Federation and Ukraine, entering
Sumy Oblast. However, this claim was denied by the head of Ukraine's Center for Combatting Disinformation,
Andriy Kovalenko, as well as senior Ukrainian military officials. The following day, Russian sources reported that soldiers from the 810th Brigade had successfully entered
Basivka, while Ukrainian sources confirmed that Russian forces had stormed the border in the Sumy Oblast. Later, on 25 February, Russian forces again claimed that they had seized
Novenke and were making progress toward northern
Zhuravka. Meanwhile, the Ukrainian military acknowledged that Russian troops had crossed the border near Novenke but stated that they had successfully pushed them back into Russian territory. On 28 February 2025, Ukraine's Center for Combatting Disinformation acknowledged that Russian forces were attacking along the international border near Basivka and Novenke. Meanwhile, DeepState described both
Basivka and Novenke as "grey zones". Around the same time, DeepState reported that Russian troops had broken through near the settlements of Novenke and Zhuravka and were reinforcing their positions. On 7 March 2025, Russian sources claimed that their armed forces had taken over
Novenke, and the next day, based on geolocation footage released, it's likely that Russian forces captured Novenke. After successfully recapturing the town of Sudzha, President Putin proposed establishing a "
buffer zone" in Sumy Oblast to protect Kursk from
future attacks. Starting on 11 March, Russian forces advanced west of Basivka and southwest of Zhuravka. in an effort to consolidate their positions in the region. A Ukrainian official claimed that Russia was massing troops along the border in preparation for an "assault" on Sumy Oblast. By 23 March 2025, Russian sources claimed their troops had moved into
Volodymyrivka. A few days later, geolocated footage indicated that Russian forces had seized the
border checkpoint between
Sumy and Sudzha to the east of Basivka. Ukrainian commander Syrskyi said that their forces are conducting a
defensive operation to prevent Russian troops from advancing further into the northern Sumy region. At the end of March 2025, geolocation footage showed that Russian forces captured
Veselivka, and the Russian Ministry of Defense also claimed that Russian troops had taken control of Veselivka. However, Ukrainian officials denied the reports of the Russian breakthrough. On 6 April 2025, footage showed Russian troops advancing south of Basivka. At the same time, Russia's Defense Minister claimed they had already seized Basivka, Between April 6 and 8, Russian troops made some temporary advances north of
Loknya, but failed to secure a foothold and got pushed back by the
4th Special Purpose Regiment. On April 9 2025, the
Commander-in-Chief of the Armed Forces of Ukraine Oleksandr Syrskyi said that Russia had already started their
Spring offensive in northeastern Ukraine (Sumy Oblast). At the same time,
Ukraine's President Volodymyr Zelenskyy mentioned that Russia has gathered 67,000 troops ready to be deployed to Sumy. On April 13 2025, Russian state media claimed that their forces had seized 70 square kilometers in Sumy Oblast. However, the
Institute for the Study of War reported that it could only confirm Russian control over 43.61 square kilometers in the region. On April 24 2025, Russian forces were confirmed to have captured
Basivka and advanced southwards into northern
Loknya. By May 8, geolocated footage showed that Russian forces have advanced to central Loknya. Russian troops took full control of Loknya by 25 May. On May 26 2025, geolocated footage showed that Russian forces seized
Bilovody, northeast of Sumy. Two days later, a Russian source claimed that Russian forces seized
Kostyantynivka and
Vodolahy, north of Sumy City but there was no footage to confirm that. On May 31, the Russian ministry of defense announced that it had taken control of the village of Vodolahy. According to an observer for
Bild, with "infantry assaults supported by motorcycles, scooters and aerial attacks, Russian forces captured at least 18 Ukrainian settlements in the final week of May." Ukraine ordered the evacuation of 11 more villages in its Sumy region; a total of 213 settlements in the region had been ordered by the end of May to evacuate. On June 1 2025, a Ukrainian source indicated Russian control over the settlements of
Oleksiivka,
Varachyne,
Yablunivka and
Novomykolaivka. On June 2, Ukrainian political scientist Viktor Bobyrenko said that Russian forces have taken the village of Kindrativka located south of Kostyantynivka. On June 5 2025,
Ruslan Mykula, co-founder of the independent Ukrainian intelligence service
DeepState UA, said that the main target of the incursion was the strategically important village of Yunakivka. Mykula believed capturing Yunakivka would provide forest cover for Russian infantry and fire control over Sumy city. In the latest report of the war by DeepState, it assessed that Russian forces occupied the villages of Kindrativka and Oleksiivka, making Russian forces within 20 kilometres of Sumy proper and Sumy within range of artillery shelling and Russian FPV drone attacks. DeepState also said that Russia is advancing to
Sadky located southeast of Yunakivka for forest cover which "will be extremely difficult to knock it out of there" if Russia succeeds. Ukrainian member of parliament
Maryana Bezuglaya and former spokesman for the General Staff of the Armed Forces of Ukraine
Vladislav Seleznyov said that all residents of Sumy must either join the defence forces or evacuate the city. On June 7–8 2025, Russian forces moved into central Yunakivka. On June 10, Russian forces took the highway in Yunakivka, cutting the town off of supplies and its logistics.
DeepStateMap.Live reported that Russian forces were 20 kilometers away from the regional capital of
Sumy. On June 22, Ukrainian forces took back
Andriivka. However, Russian forces retook the village four days later. By the end of June 2025, Ukrainian commander Syrskyi claimed that Ukraine halted further Russian advances inside Sumy Oblast. Beginning on 11–12 July, the
225th Assault Battalion launched an assault to retake the village of Kindrativka from Russian forces. After two days, the regiment had advanced up to 4 kilometers (2.5 miles) and had encircled the 30th and 40th Motorized Rifle Regiments along with the "elite"
155th Naval Infantry Brigade, each of which they claimed had just 300 to 840 men. On 17–18 July, Russian forces unsuccessfully tried to save their trapped forces, which were defeated on 24 July. During the offensive, claimed by Ukraine to be the "most substantial ground force success" since the
2024 Kursk offensive, the Ukrainians claimed to have killed, wounded or captured 700–1,000 Russian troops, including the commander of the 30th Regiment. On 22 July 2025, Ukrainian forces claimed to have retaken the village of Andriivka. On July 25 2025,
DeepStateMap.Live reported that Ukrainian forces had completely retaken the village of Kindrativka. On 27 July 2025, a spokesperson from the Kursk military group claimed that Ukrainian forces retook the village of Kindrativka. On 8 January 2026, DeepStateMap reported that Russian forces had retaken the village of Andriivka. This was denied by Ukraine. On 21 January 2026, the
State Investigation Bureau arrested a Ukrainian military officer in Sumy Oblast on "suspicion of abusing and torturing subordinates" and threatening to
shoot soldiers who failed to follow his orders. On 22 March 2026, the Russian Defense Ministry claimed to have captured the village of Potapivka. On 14 April 2026, Ukrainian military claimed that it had intercepted Russian forces trying to infiltrate Ukrainian rear positions in Sumy Oblast using gas pipelines and that 29 Russian soldiers had been killed. == Opposing forces ==