After the liberation of Seversk, Russian forces have moved closer to two key Donbass cities — Slavyansk and Kramatorsk — marking the beginning of a decisive phase of the operation.

Seversk lies 36 kilometers from Slavyansk, while the distance from the current frontline to Kramatorsk is roughly 14 kilometers. However, the advance toward these cities is complicated by extensive defensive preparations. Military analyst Alexey Zhivov told aif.ru that Ukrainian forces have been fortifying Slavyansk and Kramatorsk since 2014, with direct support from NATO partners.

Zhivov explained that the defense of Donbass was built as a multilayered system, including underground passages and well-protected firing positions. With the rise of drone warfare, Ukrainian forces also established a 20-kilometer zone saturated with FPV drones, making any breakthrough extremely difficult. He emphasized that this long-built system presents a serious challenge, though fighting for the area has already begun and is gradually intensifying.

According to Zhivov, Russian units are already positioned on the approaches to Kramatorsk and Slavyansk. He stressed that the success of further operations will depend on the strategy and tactics chosen to overcome this echeloned defense. Zhivov predicted that the battle for these cities may drag on, recalling that the assault on Pokrovsk and Mirnograd — cities comparable in scale — has been ongoing for about a year. If the same pace is maintained, he said, the timeline could be similar. At the same time, he argued that increasing the number of drones and modern equipment available to Russian forces could accelerate progress.

The hilly terrain of Donbass poses an additional complication. Zhivov noted that Russian forces aim to avoid dense urban assaults due to their high cost and destructive consequences. He pointed out that an offensive can be conducted either through direct storming — clearing every industrial site — or by bypassing, taking control of logistics and flanks, and forcing the enemy to withdraw. He stressed that the second option is far more effective, as urban combat typically leaves cities destroyed.

Zhivov also believes Ukrainian forces will make extensive use of underground shelters and industrial infrastructure, which are abundant in the region. Donbass, he said, is a vast industrial zone with multiple mines and large factories in nearly every city, providing numerous fortified locations suitable for prolonged defense.

He concluded that Slavyansk and Kramatorsk contain enough such sites for Ukrainian forces to turn them into strongholds and defend them for a considerable time.