Commander of Ukraine's Operational Command "East" steps down, grouping disbanded and split into two new forces
Major General Viktor Nikoliuk announced on 17 September that he is leaving the post of commander of Ukraine's Operational Command "East" after five months. The "East" grouping he led is being disbanded and replaced by two new formations — "Center," to be led by Andrii Biletsky, and "Azov," to be led by Denys Prokopenko.
Key points
- Major General Viktor Nikoliuk is leaving the post of commander of Operational Command "East."
- He held the position for five months, having been appointed in April 2026, replacing Brigadier General Dmytro Bratishko.
- Nikoliuk announced his departure in a Facebook post on 17 September.
- Under his command the grouping was responsible for the Sloviansk, Kramatorsk, Kostiantynivka, Ocheretyne, and Pokrovsk directions of the front.
- Nikoliuk said a fully combat-capable grouping capable of steadily conducting active defensive operations was handed over to his successor.
- The "East" grouping is being disbanded and replaced by two new groupings — "Center" and "Azov."
- "Center" will be led by Andrii Biletsky, commander of the Third Army Corps; "Azov" will be led by Brigadier General Denys Prokopenko (Redis), commander of the 1st Corps of the National Guard "Azov."
Why it matters
The departure of one of Ukraine's senior eastern-front commanders after a five-month tenure marks a significant shake-up in the command structure on the most heavily contested sectors of the front. The replacement of a single operational grouping by two new ones — led by two of Ukraine's most prominent field commanders — signals a deliberate restructuring intended to strengthen Ukrainian positions in Donetsk Oblast.
What happened
Major General Viktor Nikoliuk announced on 17 September that he is stepping down as commander of Operational Command "East," a post he had held for five months. He had been appointed in April 2026, replacing Brigadier General Dmytro Bratishko, after previously commanding the operational-tactical grouping "Donetsk." Under Nikoliuk, the grouping was responsible for the Sloviansk, Kramatorsk, Kostiantynivka, Ocheretyne, and Pokrovsk directions. Nikoliuk said the Defense Forces managed to contain the Russian advance on the Oleksandrivsk direction and to block the enemy in Kostiantynivka, and that a stable echeloned defense had been built on the Sloviansk and Kramatorsk directions. He said he was handing over to his successor a fully combat-capable grouping capable of steadily conducting active defensive operations.
The "East" grouping that Nikoliuk led is being disbanded and replaced by two new groupings: "Center," to be led by Andrii Biletsky, commander of the Third Army Corps and a Hero of Ukraine, and "Azov," to be led by Brigadier General Denys Prokopenko (Redis), commander of the 1st Corps of the National Guard "Azov." Biletsky's grouping will be responsible for the defense of the Lyman direction and the Kramatorsk-Kostiantynivka agglomeration; Prokopenko's for Dobropillia and sections of the front southwest of the city. Under Biletsky will be the 3rd, 11th, and 19th Army Corps; under Prokopenko — the 1st Corps of the National Guard, part of the 7th Corps of the Airborne Assault Forces, and the 9th Army Corps.
Background
Viktor Nikoliuk was born on 19 October 1975 in Kirovohrad Oblast and graduated from the Kharkiv Guards Higher Tank Command School and the National Defence University of Ukraine named after Ivan Cherniakhovsky. He previously commanded the 92nd Separate Mechanized Brigade, the 169th Training Centre "Desna," and Operational Command "Pivnich" (North), and led the defense of Chernihiv at the start of the full-scale invasion. He was awarded the title Hero of Ukraine on 10 March 2022. Before taking command of OK "East" in April 2026, he commanded the operational-tactical grouping "Donetsk," which he had taken over from Brigadier General Oleksandr Tarnavsky in June 2025. President Volodymyr Zelensky spoke at the end of August about creating the two new groupings intended to strengthen Ukrainian positions in Donetsk Oblast.