Russia Initiates Artillery and Drone Preparations for Anticipated Spring-Summer Offensive in Donetsk

Preparations Underway for Major Offensive

The Russian Federation has reportedly initiated significant artillery and drone preparations in Donetsk Oblast, signaling the likely commencement of a large-scale Spring-Summer 2026 offensive against Ukraine's heavily fortified 'Fortress Belt'. This development comes amidst ongoing conflict in eastern Ukraine, with recent actions indicating a shift towards intensified pre-offensive operations.

According to reports from February 27 and 28, 2026, Russian forces have engaged in artillery shelling of Bilenke, a settlement approximately 14 kilometers from the frontline and immediately northeast of Kramatorsk. This marks the first instance of Russian tube artillery striking Kramatorsk or its suburbs, suggesting the beginning of a concentrated artillery preparation phase.

Intensified Drone and Artillery Activity

Beyond artillery, Russian forces are also conducting a battlefield air interdiction (BAI) campaign, primarily utilizing drone strikes, against the southern sectors of the 'Fortress Belt'. This strategy aims to degrade Ukrainian defensive capabilities and frontline positions ahead of ground assaults. Geolocated footage from February 26 depicted Russian drone strikes targeting a civilian cyclist on the H-20 Kostyantynivka-Slovyansk highway and Ukrainian forces in Oleksiievo-Druzhkivka, both situated at the southern end of the Fortress Belt. The H-20 highway is recognized as a crucial ground line of communication (GLOC) connecting the cities within the fortified zone.

These monthslong BAI campaigns are a known Russian tactic to soften defenses before launching ground offensives. Furthermore, reports indicate a decrease in Russian infantry attacks in Sumy and parts of Kharkiv oblasts, with forces increasingly relying on drone and artillery strikes in those areas.

The Strategic 'Fortress Belt'

The 'Fortress Belt' in Donetsk Oblast is a critical defensive line for Ukraine, comprising a series of fortified cities that have formed the backbone of Ukrainian defenses since 2014. This belt includes four major cities and several smaller towns and settlements, stretching approximately 50 kilometers along the H-20 Kostyantynivka-Slovyansk highway.

• The northern half of the belt is formed by Slovyansk and Kramatorsk, which serve as significant logistics hubs for Ukrainian forces.
• The southern half includes Druzhkivka, Oleksiyevo-Druzhkivka, and Kostyantynivka.

Ukraine has invested over a decade in reinforcing this defensive line, making it a formidable obstacle for Russian forces. Analysts suggest that a Russian ground offensive to fully capture the 'Fortress Belt' would likely be a multi-year operational endeavor, demanding substantial time, manpower, and resources.

Broader Context and Recent Developments

The anticipated offensive follows the Russian seizure of Pokrovsk by late January 2026. However, significant advances beyond Pokrovsk towards the 'Fortress Belt' have not yet materialized, with the Institute for the Study of War (ISW) assessing that the 'Fortress Belt' will be Russia's primary operational focus in the coming months. A Russian milblogger has also noted that Ukrainian drone operations are currently hindering Russian logistics and personnel rotations in the Pokrovsk direction.

In preparation for sustained operations, Russia is reportedly expanding recruitment efforts within higher educational institutions to bolster its Unmanned Systems Forces (USF). Meanwhile, Ukrainian forces have recently made limited gains in the Kostyantynivka-Druzhkivka tactical area. An assessment from February 2026 indicated that Russian forces have approximately two to three months remaining in Spring 2026 to capture Kostyantynivka and Druzhkivka, which would be crucial for setting conditions for a potential summer offensive against Slovyansk and Kramatorsk.