Kyiv: President Volodymyr Zelensky has replaced Ukraine’s popular army chief with his ground forces commander, a huge gamble at a time when Russian forces are gaining the upper hand nearly two years into their war.

The shakeup ushering in a new military leadership follows months of speculation about a rift between Zelensky and army chief General Valery Zaluzhny, who many Ukrainians see as a national hero.

“As of today, a new management team takes over the leadership of the Armed Forces of Ukraine,” Zelensky said in a statement.

He named Colonel General Oleksandr Syrsky as the new head of the Armed Forces.

Syrskyi, commander of the ground forces, takes the helm amid deep uncertainty as Kyiv awaits vital military aid from the United States that has been delayed by political infighting there for months.

With Ukraine struggling to rapidly reform its army mobilisation programme, the sacking of Zaluzhny could deal a blow to the morale of troops on a 1000 kilometre front. It could also backfire politically, hurting Zelensky’s ratings.

Polling surveys put the public’s trust in Zaluzhny, known by some as the “Iron General”, at over 90 per cent – significantly higher than Zelensky’s 77 per cent late last year.

The military shakeup unfolded over a series of statements in which Zelensky said he had met Zaluzhny to discuss changes to the military leadership. He had asked the general to remain “on his team,” he said.