Ukrainian troops are involved in very tough fighting near the strategically importanteastern town of Bakhmut, which Russia is trying to take, President Volodymyr Zelenskiy said in video address on Saturday. Although Ukrainian troops have recaptured thousands of square kilometres (miles) of land in recent offensives in the east and south, officials say progress is likely to slow once Kyiv’s forces meet more determined resistance. Russian forces have repeatedly tried to seize Bakhmut, which sits on a main road leading to the cities of Sloviansk and Kramatorsk. Both are situated in the industrial…