Russia withdraws from key areas in Ukraine's east after surprise offensive

Ukrainian forces kept up their surge in the country's east Saturday after punching through Russian defenses in a surprise counteroffensive that could prove a decisive turning point in the war.

Kyiv said its military had recaptured swaths of territory in a fast-moving thrust centered on the region around Kharkiv, Ukraine's second-largest city, that threatened to turn into a much broader rout. After days of silence on the subject, Russia's defense ministry said it was withdrawing troops from two key areas.

“The Russian army in these days is showing the best that it can do —...