Russian forces have launched an offensive on the "fortress belt" in Donetsk Oblast, — ISW

Analysts at the Institute for the Study of War (ISW) reported that Russian forces have launched the planned spring–summer 2026 offensive against the Ukrainian «fortress belt» — the main line of defense in Donetsk Oblast. According to ISW, one of the initial directions was a movement toward Lyman, which opens an approach to Slov’iansk from the northeast and is intended to prepare the ground for subsequent phases of the operation. The report emphasizes:

«Russian forces have begun ground operations toward Lyman with the aim of advancing on Slov’iansk, the northern edge of the Fortress belt, from the northeast, likely to create conditions for a subsequent assault on Slov’iansk from the east and southeast in later phases».

ISW emphasizes that Lyman is a key strongpoint on the approaches to Slov’iansk and could become a base for further strikes on Slov’iansk and Kramatorsk. Over the 24-hour period on 19 March, offensive actions were recorded on 7 directions involving more than 500 infantry, dozens of armored vehicles and over 100 motorcycles, buggies and all-terrain vehicles.

A representative of a Ukrainian mechanized brigade reported that the enemy is increasing pressure through the mass use of infantry and equipment, and is also adapting tactics by dispersing assault groups from multiple directions. At the same time, Russia is extensively using guided aerial bombs KAB-3000, loitering munitions «Lancet» and strike drones «Molniya». Analysts conclude:

“These air strikes and drone attacks are likely aimed at degrading Ukrainian logistics and defenses ahead of ground operations”.

At the same time the enemy is creating preconditions to intensify actions on the southern sectors of the fortifications. Lieutenant Colonel Dmytro Zaporozhets noted that the enemy is actively redeploying personnel to Kostiantynivka, increasing drone attacks from the Chasiv Yar area, moving up armored vehicles and doubling the intensity of artillery and air strikes toward Kramatorsk.

The ISW report emphasizes that such actions have the clearly defined aim of preparing for the next phases of the campaign:

“Russian forces are intensifying ground assaults and strikes, and the transfer of heavy equipment and troops to the front line is intended to create conditions for the spring–summer 2026 offensive”.

Previously we wrote:

• The Armed Forces of Ukraine foiled Russia’s strategic offensive planned for March — Zelensky
• Russian forces advanced on three directions over 24 hours, – reports DeepState
• Zelensky warned of a Russian spring offensive in Donbas
• Occupiers advanced toward Kramatorsk and in the Pokrovsk area
• NATO said that Ukraine needs another 250,000 troops to turn the tide in the war