After suffering a humiliating defeat during the largest armed conflict in Europe since World War II, Russia began targeting Ukrainian energy infrastructure in October.
The attacks have caused widespread blackouts, and cut water supplies and heating to civilians, at a time when temperatures have dropped to minus five degrees Celsius (41 degrees Fahrenheit) in some areas.
Authorities have scheduled power cuts several times a day to keep essential infrastructure working.
On Saturday, the governor of the southern region of Mykolaiv, Vitaly Kim, urged citizens to “endure” the power outages.
Putin told German Chancellor Olaf Scholz on Friday that the Russian attacks, which have destroyed half of the Ukrainian energy system, were an “inevitable response to Kyiv’s provocative attacks on Russia’s civilian infrastructure”.