Commanders of units stationed at the city's massive Azovstal steelworks plant have been ordered "to save the lives of their personnel," the statement by the General Staff of the Armed Forces of Ukraine also said.

Hundreds of people were evacuated on Monday from the steel plant, the last holdout in a city that had become a symbol of Ukrainian resistance under relentless Russian bombardment.

Ukraine's Deputy Defense Minister Hanna Malyar described the evacuation operation in a separate video statement, noting that some Ukrainian forces remain at Azovstal.

"Fifty-three seriously injured people were evacuated from Azovstal to a medical facility in Novoazovsk for medical care," she said.

"Another 211 people were taken to Olenivka through the humanitarian corridor."

An "exchange procedure" will see the evacuees eventually brought home, Malyar also said.

"Ukraine needs Ukrainian heroes alive," Ukrainian President Volodymyr Zelensky said Monday in a statement about the evacuation, thanking the Ukrainian military and negotiators, the International Committee of the Red Cross and the United Nations.

"The 82nd day of our defense is coming to an end.