Ukraine and its allies have reported that Russian troops are withdrawing from around Kyiv and Chernihiv, shifting focus to the country's east.
Ukrainian presidential advisor Mykhailo Podolyak said on Saturday that Russia is prioritising moving east and south to control the occupied territories there.
Podolyak said he thinks Russia will try to create a strong foothold in the east with the support of air defence.
Ukrainian President Volodymyr Zelenskyy warned that he expects departed towns to endure strikes from afar and for the battle in the east to be intense.
He also said the retreating forces were also leaving leaving mines around homes, abandoned equipment and “even the bodies of those killed."
“It’s still not possible to return to normal life, as it used to be, even at the territories that we are taking back after the fighting. We need wait until our land is de-mined, wait till we are able to assure you that there won’t be new shelling,” the president said during his nightly video address, though his claims about Russian mines couldn't be independently verified.
The focus on eastern Ukraine has kept the besieged port city of Mariupol in the crosshairs.
Military analysts think Russian President Vladimir Putin is determined to capture the Donbas region after his forces failed to secure Kyiv and other major cities.
The International Committee of the Red Cross planned to try Saturday to get into Mariupol to evacuate residents. The Red Cross said it could not carry out the operation Friday because it did not receive assurances the route was safe. City authorities said the Russians blocked access to the city.
The humanitarian group said a team with three vehicles and nine Red Cross staff members was headed to Mariupol on Saturday to help facilitate the safe evacuation of civilians. It said its team planned to accompany a convoy of civilians from Mariupol to another city.
“Our presence will put a humanitarian marker on this planned movement of people, giving the convoy additional protection and reminding all sides of the civilian, humanitarian nature of the operation,” it said in a statement.
Meanwhile, Ukrainian authorities listed several humanitarian corridors to help civilians leave the east of the country.