President Volodymyr Zelensky on Sunday insisted that the east Ukrainian city Bakhmut -- which Moscow claimed to have captured a day earlier -- was "not occupied," according to AFP.

"Bakhmut is not occupied by Russia today," Zelensky told a press conference during the G7 summit in Hiroshima.

"They are in Bakhmut," he said, not clarifying if that referred to Russian or Ukrainian troops.

"I cannot share with you the tactical views of our military. The most difficult thing would be if there was some tactical mistake in Bakhmut and our people were surrounded," he said.

Ukraine has denied Russian claims made on Saturday that it had fully captured the city after the longest battle of the war.

Deputy Defence Minister Ganna Malyar has instead claimed that Ukrainian troops are advancing "in the suburbs on the flanks", which would make it "very difficult for the enemy to be in Bakhmut."

Ukrainian soldiers have "semi-encircled the city," she said, adding that Ukraine was still in control of a residential area and some industrial facilities.