The Ukrainian government has approved President Petro Poroshenko’s proposal to appoint colonel-general Valery Heletey as the new defence minister.
Lieutenant-general Viktor Muzhenko is to become head of the general staff. He has been an integral player in the military drive against rebels in the east of the country.
The shake up follows Poroshenko’s decision to resume a full offensive against the separatists.
Speaking in parliament in Kyiv, the president said: “The Ukrainian army needs a new commander – a military man who knows how to fight and has experience on the ground. A general who knows what a war by proxy is and understands how to win it.”
Security officials advised Poroshenko not to prolong a shaky ceasefire in the east, saying it had given insurgents time to regroup and rearm.
The US has expressed support for the decision. Russia, meanwhile, has harshly condemned the move to relaunch operations.
Moscow refutes Kyiv’s accusations that it is stoking the conflict by reinforcing the separatists.
Following talks with France and Germany, both the Russian and Ukrainian foreign ministers have backed the idea of a further meeting with rebel leaders, to push for a lasting truce.