Ukrainian troops are advancing in two directions in the eastern city of Bakhmut but the situation in the city centre is more complicated, deputy defence minister Hanna Malyar said on Saturday.
Ukrainian and Russian officials both say pro-Kyiv forces have started to push back in and around Bakhmut after blunting a months-long offensive by troops loyal to Moscow that left much of the city in ruins.
Russia acknowledged on Friday that its forces had fallen back north of Bakhmut ahead of a long-promised counter offensive by Ukraine to retake more territory it lost after the start of the war last year.
"Our troops are gradually advancing in two directions in the suburbs of Bakhmut ... however, the situation in the city itself is more complicated," Malyar wrote on Telegram.
"Thanks to the competent planning of the command and the courage of our fighters, the enemy is not able to take the city under its control."
Ukrainian President Volodymyr Zelenskiy, in Rome for an official visit, did not respond directly when asked when the counter offensive would start.
"I can't answer this question but you will see the results and Russia will feel them," he told Italian television.
(Reporting by David Ljunggren in Ottawa and Gavin Jones in Rome; Editing by Daniel Wallis)