KYIV (Reuters) -Ukraine's top military commander Oleksandr Syrskyi warned on Saturday of a possible new Russian offensive in the Kharkiv region, a part of northeastern Ukraine which has seen heavy fighting since Russia invaded in 2022. Russian forces have already pushed into northern Ukraine's Sumy region over the past months, carving out a small foothold there. "I dedicated two days to working with units in Kharkiv region," Syrskyi wrote in a post on the Telegram app.