Ukraine’s so-called “fortress belt” is reportedly under threat as Russia seeks to advance.

Vladimir Putin’s forces are looking to make gains on the battlefield in an effort to threaten the southern tip of four eastern Ukrainian cities fiercly defended by Volodymyr Zelensky’s troops.

The belt includes Kostyantynivka, Druzhkivka and Kramatorsk.

Kostiantynivka is a city in Donetsk Oblast, in eastern Ukraine. It is located on the Kryvyi Torets river, and, during the Soviet era, was a major producer of iron, zinc, steel and glass.

Druzhkivka was the largest single producing area of iron and steel in Ukraine. Kramatorsk had also developed from the end of the 19th century, particularly its metallurgical industry, and the production of iron and steel.

The Institute of the Study of War (ISW) stated in its daily report for January 7 that Russian forces likely intend to exploit their advances in northwestern Toretsk to push further west of Toretsk and Shcherbynivka, and along the T-05-16 Toretsk-Kostyantnivka highway towards the southernmost point of Ukraine‘s fortress belt in Kostyantynivka.

It added: “Russian forces may intend to consolidate their positions in northwestern Toretsk and central Shcherbynivka (west of Toretsk) to advance along the T-05-16 highway towards Kostyantynivka through Nelipivka, Pleshchiivka, and Ivanopillia and the fields around these settlements in an effort to threaten the southern tip of Ukraine‘s Kostyantynivka-Druzhkivka-Kramatorsk fortress belt, which forms the backbone of Ukraine‘s Donetsk Oblast defense.”

Experts believe Russian forces may also attempt to leverage further advances northwest of Toretsk and south of Chasiv Yar towards Bila Hora and Oleksandro-Shultyne in order to “collapse” the Ukrainian pocket in this area, and level the frontline west and southwest of Kostyantynivka.

It is thought that such advances would complicate Ukraine‘s ability to counterattack into Russia‘s near rear southeast of Chasiv Yar, including towards Klishchiivka, and would allow Russian forces to deploy additional artillery systems within range of Kostyantynivka and operate first-person-view (FPV) drones within range of the town.

The ISW also reported: “Russian forces may also attempt to advance west and northwest of Niu York and Leonidivka towards the H-20 Donetsk City-Kostyantynivka highway and H-32 Pokrovsk-Kostyantynivka highway to pressure Kostyantynivka further from the south and create a more stable southern flank for a push on Kostyantynivka.

“Russian forces will likely be able to accomplish more rapid advances in the fields and small settlements north and west of Toretsk than they have been able to make in their grinding advances in urban Toretsk.

“Russian units in this area may attempt to replicate the short, tactically significant mechanized assaults that Russian forces conducted in the Kurakhove and Vuhledar directions in Fall 2024 if they have adequate armored vehicle reserves for this sector.”