Ukraine's new army head Oleksandr Syrsky, who was appointed in Kyiv's largest military shake-up since Russia invaded, is taking the helm at a precarious moment in the war.
After nearly two years of fighting, these are the five most pressing challenges the 58-year-old commander, who was born in Russia, is facing.
Ukraine's allies, particularly Washington and Brussels, are struggling to keep up aid packages that have so far allowed Kyiv to hold out against Russia.
The EU this month unblocked 50 billion euros in aid, but US senators have only managed to clear a first hurdle to a potential future package after months of political deadlock.
The uncertainty over Ukraine's resources come as Russia turns it economy to a war footing, ramping up production and recruitment.
Ukraine's military and political leadership are at odds over how to replenish the army's ranks, following two years of costly fighting that Washington believes has killed around 70,000 Ukrainian soldiers.
Yet even after the West bolstered Ukraine's air defence systems, securing ammunition for those weapons remains an issue.
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