Ukraine and Russia ended a second day of US-brokered talks in Abu Dhabi on Saturday without a deal, but future meetings are considered.
This after overnight Russian airstrikes knocked out power for over a million Ukrainians amid subzero winter cold.
Consumers in the Chernihiv region, including the regional centre, remain without electricity after a Russian strike on critical infrastructure.
Municipal workers deployed power generators across the city to restore energy supply.
In Kharkiv, overnight Russian attacks injured at least 19 people, and damaged a number of residential buildings.
Several hospitals were among those damaged, while some people were trapped under the rubble.