Mr Putin made the comments during an hour long phone call with French President Emmanuel Macron on Tuesday night, the Kremlin said in a statement.
But French officials said the Russian leader had agreed to consider plans to evacuate civilians from the city.
Russia has since proposed a one-day ceasefire for Thursday.
The defence ministry said the ceasefire would start at 10:00 local time (08:00 BST) and would allow people to travel westwards to Zaporizhzhia vie the Russian-controlled port of Berdyansk.
