Ukraine's industrial Donbas region, the focus of recent Russian offensives, has been destroyed, President Volodymyr Zelenskiy said as some of the world's richest countries pledged to bolster Kyiv with billions of dollars.

Since turning away from Ukraine's capital, Russia is using massed artillery and armour to try to capture more territory in the Donbas, comprised of the Donetsk and Luhansk areas, which Moscow claims on behalf of...