The move came as Kyiv has struggled to hold back Moscow's forces in the east for months, almost two and half years into the war.

"I have decided to replace the Commander of the Joint Forces of the Armed Forces of Ukraine, Lieutenant General Yuriy Sodol, with Brigadier General Andriy Gnatov," Zelensky said in his daily evening address.

He gave no details on the reasons for the dismissal but the decision came after criticism from a commander of the Azov brigade, known for its links with the far right.

The Azov commander, Bogdan Krotevych, had a day earlier filed a complaint to the SBU security service, calling for an investigation into Sodol.

According to media reports, Krotevych accused Sodol of incompetence and blamed him for the death of Ukrainian soldiers at the front.

Ukraine -- outgunned and outmanned by Russia -- has been on the back foot for months, with Moscow's forces claiming new villages in the east almost every week, but without making a major breakthrough.