By Pavel Polityuk and Phil Stewart IZIUM, Ukraine (Reuters) -The top U.S. general warned on Sunday it was unclear how Russia would react to its battlefield setbacks in Ukraine, as Britain said Moscow’s forces had widened strikes on civilian infrastructure and were likely to expand their targets further. Ukraine’s General Staff said Ukrainian forces repelled attacks by Russian troops in the areas of the Kharkiv region in the east and Kherson in south where Ukraine launched counter-offensives this month, as well as in parts of Donetsk in the southeast. Ukrainian President Volodymyr Zelenskiy vow…