Kyiv was subjected to new Russian attacks on Wednesday.
Nearly 6,000 buildings in the city were without electricity in the early evening, according to Klitschko. Only 400 of those can expect heat to be restored during the day.
On Tuesday, Klitschko said, according to the Kyiv Independent, that 70 percent of the capital lacked electricity, and a day later he said the situation was still "very difficult."
President Volodymyr Zelenskyy said in a statement that the attacks on electricity supplies have put the entire energy sector in a state of emergency.
"A permanent coordination office will be opened to sort out the situation in Kyiv," he said in a statement.
According to the BBC, temperatures will drop to -18 degrees in Kyiv overnight.
