Ukraine reclaims 176 square kilometres in Donbas offensive Operation Vivaldi

Ground offensive in the Lyman sector

Ukrainian President Volodymyr Zelensky visited the command post of the Third Army Corps along the Lyman front in Donetsk Oblast on Wednesday to evaluate the results of Operation Vivaldi. According to Ukrainian military officials, the operation regained control of 176 square kilometres of territory across three completed operational phases. The advance halted Russian attempts to penetrate into the rear areas of the Slovyansk-Kramatorsk urban agglomeration and stabilized front lines across the region. During his visit, Zelensky met with unit commanders to review frontline equipment requirements and artillery munitions, while also presenting state awards to participating servicemen. Planning has already begun for a fourth phase of active operations to extend Ukrainian control.

During its three seasons, the Defense Forces of Ukraine thwarted Russian plans to break through into the rear of the Slovyansk-Kramatorsk agglomeration and stabilized the situation on this section of the front.

Deployment of unmanned ground combat systems

The Ukrainian military attributed much of the tactical progress in north-western Donbas to the deployment of robotic ground systems. Unmanned ground vehicles moved into position under cover of darkness, opening fire directly behind Russian positions and causing defending troops to break formation. Ukrainian commanders stated that multiple Russian detachments surrendered in full after encountering the automated combat units. Officials indicated that the offensive compromised Russian timelines aimed at seizing the remainder of Donetsk Oblast before the end of the year. The Ukrainian general staff plans to broaden the deployment of automated systems across active combat zones to shield infantry from frontline hazards.

A very promising direction right now is replacing our soldiers with ground robotic systems wherever possible. During Operation Vivaldi, this particular element allowed us to achieve a great deal.

Battlefield casualties and captive counts

Ukrainian officials reported that Russian forces sustained more than 5,000 personnel killed and wounded during Operation Vivaldi, alongside 250 soldiers taken prisoner for exchange funds. British military intelligence reported that Russian forces suffered 2,090 casualties on 27 September alone, marking the highest single-day loss recorded for the Russian military since the full-scale invasion began in 2022. The 2,000-casualty mark had previously been reached on only three occasions, all in 2024. British assessments linked these elevated losses to persistent Russian assaults against the Ukrainian fortress belt in Donetsk Oblast. Separate research by Mediazona and the BBC Russian service has confirmed the identities of approximately 260,000 killed Russian soldiers, a count researchers note covers only 45% to 65% of the overall death toll due to Russian state non-disclosure.

Diplomatic contacts and regional military exercises

In parallel with frontline developments, Zelensky conducted bilateral talks on Wednesday with Norwegian Prime Minister Jonas Gahr Støre to address air defense requirements and fleet maintenance for F-16 fighter jets. The discussion followed Russian drone and ballistic missile strikes that killed seven civilians, including one child, and wounded 24 people earlier in the day. Meanwhile, the Collective Security Treaty Organization initiated joint military exercises at the Chebarkul training ground in Russia. The drills, titled Interaction, Search, and Echelon, involve approximately 2,000 military personnel from Russia, Belarus, Kazakhstan, Kyrgyzstan, and Tajikistan practicing border conflict responses.