By Tom Balmforth and Yuliia Dysa KYIV (Reuters) -Russian forces have captured four villages in Ukraine's northeastern Sumy region, the local governor said, the latest battlefield setback for Kyiv as it seeks to hold territory and avoid handing Moscow the advantage in any peace talks.

Russia fired its biggest-ever drone barrage on Ukraine on Monday, Kyiv said, escalating a deadly air campaign that analysts say offers little military value and instead appears intended to erode civilians’ morale.

Russia launched over 900 drones at Ukraine over the weekend and comes after U.S.-led efforts last week to reach a ceasefire between the two countries.