The biggest shake-up of Ukraine's government since the start of Russia's full-scale invasion underlines President Volodymyr Zelenskyy's need to show key Western partners and war-weary Ukrainians that he is serious about tackling corruption and punishing misrule.

The abrupt exit of more than a dozen officials in recent days followed a series of scandals and graft allegations, including one involving the Defense Ministry that had sparked a public outcry despite being denied.

Ukraine's long-running struggle with graft has taken on added significance as Kyiv battles for survival while also pursuing a bid to join the European Union.